# Building a SP125C / 101B Kart Saw



## blsnelling (Nov 9, 2011)

This thread is to document me being overcome by yellow fever, lol. I bought a 797 that showed up on Monday. Then yesterday a SP125C came that I will be building with a 101B kart block, as well as some other go fast goodies. Then today, another SP125C showed up that already has a 101 block in it. It lost compression. I will be going through it and sending it back to it's owner.

Here are the three saws. The first one here is a Super 797 I just bought off eBay. It's very clean and runs great. I plan on leaving this one entirely stock..

<iframe width="640" height="360" src="http://www.youtube.com/embed/EzrXjKRf5FU?rel=0" frameborder="0" allowfullscreen></iframe>


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## blsnelling (Nov 9, 2011)

This is the SP125C that I will be building for myself using a 101B block, sloper intake, BDC or Tilly HL carb, and some kind of performance muffler. It's going to be prettied up with some chrome and flashy colors, yet to be decided.


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## blsnelling (Nov 9, 2011)

This is the one that already has a 101B block. However, it lost compression and will need a going through. I'm doing the work and sending it back to it's owner. I will be doing this saw before I build mine.


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## blsnelling (Nov 9, 2011)

Now, here are the parts I have to work with for my 101B build. This cylinder obviously need bored out. I have a .030" over piston, but I don't think that will clean it up. How far can you go with these?


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## blsnelling (Nov 9, 2011)




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## blsnelling (Nov 9, 2011)

I have two pistons.












This one is said to be .030" over.










It appears that perhaps this cylinder has already been bored before, although I'm not sure how much.





Here are some misc parts.


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## blsnelling (Nov 9, 2011)

That's all the pics for now.


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## cpr (Nov 9, 2011)

I've heard as much as .070 over. Your 101 block has been ported. The transfers look fine, but the exhaust has been raised. Be curious to see how that plays out. My ported one has been raised more, but that one will be piped, alky as that's what it was built for.

Looking forward to this!


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## ptjeep (Nov 9, 2011)




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## Ambull (Nov 9, 2011)

If the cylinder is shot, I think it is possible to re-sleeve them. Probably costs a bit more. Then the exhaust raising issue could be fixed.

Subscribing!!


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## Jacob J. (Nov 9, 2011)

That one gouge goes pretty deep. I doubt that one will clean up even going .070" over. The largest piston made by the factory was .050" over and the largest piston Wiseco made was .095" over. Supposedly there's an ART piston out there somewhere that's .110" over but by that point the sleeve is so thin it's ruined. That block might have to be re-sleeved (it's been "needled" pretty hard.)

The 84470 piston is .010" over and the 84474 piston is listed as .030" over. The intake side transfers have some pretty shoddy looking porting. I'm real leery of "ported" kart blocks because there was a lot of hacks back in the 60's and 70's chopping up these blocks. I only buy blocks with stock ports.


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## cpr (Nov 9, 2011)

True JJ. The only reason I agreed to buy the ported one that I have is because I know and trust the guy who ported and assembled it.


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## Freehand (Nov 9, 2011)

opcorn:


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## leeha (Nov 9, 2011)

Nice project Brad.
Looks like the 101 block is at .020 over already.
I have a 797 that has an aftermarket .070 piston
in it. And brian13 has a 797 with an .080 in his.
You have some pretty good gouges in your block.
Looks like a wrist pin bearing failure. I would be
surprised if it cleans up since it is already at .020
over. If it we me, I would look for another stock 
block. Just my opinion.




Lee


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## Brian13 (Nov 9, 2011)

leeha said:


> Nice project Brad.
> Looks like the 101 block is at .020 over already.
> I have a 797 that has an aftermarket .070 piston
> in it. And brian13 has a 797 with an .080 in his.
> ...



Mine was .80 over and it was a Wiseco piston. I just saw on on ebay an month or two ago advertized a .100 over. Think it was Wiseco as well. Looking forward to watching these builds.


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## procarbine2k1 (Nov 9, 2011)

Yellow fever? Took ya long enough!


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## ale (Nov 9, 2011)

This is all over my head but I'm looking forward to learning something. Good thread!


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## Jacob J. (Nov 9, 2011)

Brian13 said:


> Mine was .80 over and it was a Wiseco piston. I just saw on on ebay an month or two ago advertized a .100 over. Think it was Wiseco as well. Looking forward to watching these builds.



Actually I think that was a Fuller piston advertised as Wiseco.


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## procarbine2k1 (Nov 9, 2011)

McCulloch Super Pro 125 with a 101b Kart Engine .................

I love the look of the 101B cover as seen on the link above. If you are going for some flash, I love the red white and blue.


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## Teddy.Scout (Nov 9, 2011)

Have #2 .100 pistons, labeled as "special" for the 101 series boxed by Wiseco.

After what JJ said, safe to assume a resleeve is due after .080.

Will see if the next one can be ground to .130 and sleeved accordingly.
(be awhile for that, ya know, CAD funds and all!!!!)


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## 54stude (Nov 9, 2011)

I am really interested in seeing how you can get these saws to run in comparison to ported 6 cube modern saws!


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## rwoods (Nov 9, 2011)

Brad, I'm no expert but are you sure that you have a 101B block? Looks to me like your block has a plug for a dsp port and I can't make out the booster bumps on the flywheel side. You can compare blocks when you tear down the other saw. Whatever model yours is, the ports aren't stock. Ron


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## Jacob J. (Nov 9, 2011)

You can see the boost ports in the first picture of the interior of the cylinder, looking down. 

I've seen other 101 blocks that had the compression release on the side.


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## blsnelling (Nov 9, 2011)

Thanks for all the input. I'll need it here. This is virgin territory for me. Yeah, I'm concerned about this block. So the concensus is that .080 is the safe maximum? Anyone have a line on a piston? It does look like the exhaust has been raised a lot. It's at a really steep angle upwards. I'll be comparing it to the other block once I get it torn down. Hopefully it's stock. At worse, I guess I'll have to get a pipe and an alky carb, lol. No, I want this to run on gas and muffler.


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## Jacob J. (Nov 9, 2011)

Brad-

Randy Duncan has a lot of the oversized pistons. I bought a .095" over Wiseco from Hansen Duncan (Randy's dad) when he was still alive and he had five more of them at the time. As much as a pain as Randy is to deal with, he has thousands of desirable NOS kart and saw parts for many brands.


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## blsnelling (Nov 9, 2011)

Jacob J. said:


> Brad-
> 
> Randy Duncan has a lot of the oversized pistons. I bought a .095" over Wiseco from Hansen Duncan (Randy's dad) when he was still alive and he had five more of them at the time. As much as a pain as Randy is to deal with, he has thousands of desirable NOS kart and saw parts for many brands.



He's not that far from here either. I'm in contact with the guy I'm getting the sloper V4 from and he has pistons too. I'm checking to see what's available from him. He's been a pleasure to deal with.


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## Jacob J. (Nov 9, 2011)

blsnelling said:


> He's not that far from here either. I'm in contact with the guy I'm getting the sloper V4 from and he has pistons too. I'm checking to see what's available from him. He's been a pleasure to deal with.



Yeah Herb is a good old boy for sure. 

Hansen was a prince among men. It was a real sad day for gearheads everywhere when he passed on.


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## blsnelling (Nov 9, 2011)

Jacob J. said:


> Yeah Herb is a good old boy for sure.
> 
> Hansen was a prince among men. It was a real sad day for gearheads everywhere when he passed on.



Actually Herb Sr. is in FL for a wedding. I've been dealing with Herb Jr. He's been a pleasure to deal with, although needs help from Sr. finding some of the stuff.


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## Anthony_Va. (Nov 9, 2011)

I'm excited to see these builds. I wish they were mine though. :biggrin:


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## MechanicMatt (Nov 9, 2011)

opcorn:


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## parrisw (Nov 9, 2011)

Cool, I've always wanted to do up a cart saw. One day, one day!


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## Jacob J. (Nov 9, 2011)

parrisw said:


> Cool, I've always wanted to do up a cart saw. One day, one day!



You can do up a SP-125 first. I still have one here with your name on it.


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## parrisw (Nov 9, 2011)

Jacob J. said:


> You can do up a SP-125 first. I still have one here with your name on it.



Nice. :msp_thumbsup: See what we can work out after the 390 trade is all said and done.

Will


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## blsnelling (Nov 10, 2011)

Anyone have a line on any oversized pistons? I'm afraid that I need to go as big as possible to clean this one up.


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## Jacob J. (Nov 10, 2011)

blsnelling said:


> Anyone have a line on any oversized pistons? I'm afraid that I need to go as big as possible to clean this one up.



Did you contact Randy Duncan?


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## blsnelling (Nov 10, 2011)

Jacob J. said:


> Did you contact Randy Duncan?



I sent him a message through Ebay a few minutes ago. I'm waiting to hear back from Herb Jr as well.


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## William Balaska (Nov 10, 2011)

There are companys that will repair that cylinder and make it work for that piston, why not just have it repaired?


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## blsnelling (Nov 10, 2011)

William Balaska said:


> There are companys that will repair that cylinder and make it work for that piston, why not just have it repaired?



Got names or links? I assume you're talking about putting a new sleeve in it?


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## MechanicMatt (Nov 10, 2011)

Brad we re-sleve blocks at the car dealership all the time, I think if you can hunt down a sleave any competent machine shop can handle the task. We use a screw press to pull the sleve into place. MAN I WISH I KNEW HOW TO SPELL SLEAVE SLEVE GOSH DANG IT! 





ARGH SLEEVE! I read it after I posted this and Im to lazy right now to fix it


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## Jacob J. (Nov 10, 2011)

L.A. Sleeve used to do a lot of these kart blocks and the fixed head saw blocks as well. Back in the day they got some tooling and sleeves directly from McCulloch as McCulloch was going out of business. It's going to be easier (and probably) cheaper to just find another 101 block rather than have that one sleeved.


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## Brian VT (Nov 10, 2011)

Jeez, I came back on page 3 thinking Brad would have a video of it cutting by now (since he never sleeps). LOL



Jacob J. said:


> It's going to be easier (and probably) cheaper to just find another 101 block rather than have that one sleeved.



I guess I'll check back in on page 6. LOL


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## blsnelling (Nov 10, 2011)

Brian VT said:


> Jeez, I came back on page 3 thinking Brad would have a video of it cutting by now (since he never sleeps). LOL
> 
> 
> 
> I guess I'll check back in on page 6. LOL



I'm trying to tell myself that this doesn't have to be done in a week. I've got other irons in the fire and it takes time to find and acquire the parts for these oldies.


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## cpr (Nov 10, 2011)

Not certain if they have done it before, but if anyone can, try calling RM Motorsports in Wixom, MI. Ask for Craig Bennett. He built and ported my other 101 for Alex Ortiz before I bought it.


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## Dennis Cahoon (Nov 10, 2011)

There's a ton of those blocks better than that scraped up junker still around. I've got 2 or 3 rotting in my Mac junk pile......but you ain't gettin one Brad......Hahahahahahaha!


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## blsnelling (Nov 10, 2011)

Dennis Cahoon said:


> There's a ton of those blocks better than that scraped up junker still around. I've got 2 or 3 rotting in my Mac junk pile......but you ain't gettin one Brad......Hahahahahahaha!



Ahh, you big putty tat. You know you want to sell me one. If you're too shy to say so publically, you can always PM me


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## parrisw (Nov 10, 2011)

Dennis Cahoon said:


> There's a ton of those blocks better than that scraped up junker still around. I've got 2 or 3 rotting in my Mac junk pile......but you ain't gettin one Brad......Hahahahahahaha!



Your too kind Dennis! hahahahahahahahahahahahahahahahahahahahahahahahahahahahahahahahahah hahahahahahahahahahahahahahahahahahahahahahahahahahahahahahahahahah hahahahahahahahahahahahahahahahahahahahahahahahahahahahahahahahahah hahahahahahahahahahahahahahahahahahahahahahahahahahahahahahahahahah


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## NORMZILLA44 (Nov 10, 2011)

AAta boy Brad! NIce saw's. JJ mentioned wiseco, name I haven't heard since well along time. My dirt bike day's put em in our bike's, and they were real popular. Will see ya on the SS island thread.


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## Jacob J. (Nov 10, 2011)

The last 101 block I got off ebay was only $65 total. It was an .008" over needled block that had a Burris piston in it (Burris made a bunch of odd-sized pistons for the Macs- .008", .016", .024", .032".) I had Terry Ives bore it for a .030" over piston. He charged me 90 bucks and that was with the new piston and rings and shipping.


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## parrisw (Nov 10, 2011)

You guys are all wrong. I'd put it together and run it with a can of "Engine Restore"


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## Dennis Cahoon (Nov 10, 2011)

blsnelling said:


> Ahh, you big putty tat. You know you want to sell me one. If you're too shy to say so publically, you can always PM me



Nope!......wouldn't sell you Jack! 


Lick your lips and lust Brad......Hahahahahahaha!


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## youngs24 (Nov 11, 2011)

Dennis Cahoon said:


> Nope!......wouldn't sell you Jack!
> 
> 
> Lick your lips and lust Brad......Hahahahahahaha!





Hey Dennis how much for me? It sure would look good in my collection back here in Virginia Thanks Troy!


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## blsnelling (Nov 11, 2011)

Jacob J. said:


> The last 101 block I got off ebay was only $65 total. It was an .008" over needled block that had a Burris piston in it (Burris made a bunch of odd-sized pistons for the Macs- .008", .016", .024", .032".) I had Terry Ives bore it for a .030" over piston. He charged me 90 bucks and that was with the new piston and rings and shipping.


I'd love to come across a deal like that!


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## 7oaks (Nov 11, 2011)

Dennis Cahoon said:


> There's a ton of those blocks better than that scraped up junker still around. I've got 2 or 3 rotting in my Mac junk pile......but you ain't gettin one Brad......Hahahahahahaha!



I wanna know Dennis...Is there a code behind the number of Haha's you put in each message?


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## woodworkorange (Nov 11, 2011)

Just curious (and I apologise if its been asked before) but how much does a SP125 weigh (before the kart engine goes in it :msp_smile: )


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## cpr (Nov 11, 2011)

woodworkorange said:


> Just curious (and I apologise if its been asked before) but how much does a SP125 weigh (before the kart engine goes in it :msp_smile: )



Not sure, but it gets lighter when it's singing its song... weird.


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## blsnelling (Nov 11, 2011)

I just got off the phone with Terry Ives. I'm going to send this block to him for boring. He has up to .068" oversized pistons. If that doesn't do it, I think I can source a .090"over piston. It depends on the block how far you can go. He's got the experience to be able to tell. $150 for bore and piston doesn't sound too bad. I'll also have him look at that exhaust port to see of it's too high.


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## blsnelling (Nov 11, 2011)

Options are beginning to open up. I believe I have found a good block. I won't know for sure, or have a price until next week.

What do you guys know about a Reed sloper intake that takes a Go Power 6-petal reed block? A Tilly HL bolts on directly. They originally came with a early flatback carb?

Who makes this V4 sloper that I have coming? Is that a Gem product?


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## leeha (Nov 11, 2011)

Just got off the phone with a good buddy
out in Chico Ca. I may have a rebuildable 101
for my SP125 project. Been meaning to do this
for quite some time. This thread gave me a
good kick.





Lee


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## 54stude (Nov 11, 2011)

Jacob J. said:


> The last 101 block I got off ebay was only $65 total. It was an .008" over needled block that had a Burris piston in it (Burris made a bunch of odd-sized pistons for the Macs- .008", .016", .024", .032".) I had Terry Ives bore it for a .030" over piston. He charged me 90 bucks and that was with the new piston and rings and shipping.



Could you please elaborate what a "needled" block is?


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## cpr (Nov 11, 2011)

I started working on mine, get rwoods going and 4 of us are doing it. Another AS build-off, lol?


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## cpr (Nov 11, 2011)

54stude said:


> Could you please elaborate what a "needled" block is?



Pitch a needle out of the rod and score the liner.


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## 54stude (Nov 11, 2011)

cpr said:


> Pitch a needle out of the rod and score the liner.



Ahhh. Here I was thinking it was some trick shot peening process or something.


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## blsnelling (Nov 11, 2011)

blsnelling said:


> Options are beginning to open up. I believe I have found a good block. I won't know for sure, or have a price until next week.
> 
> What do you guys know about a Reed sloper intake that takes a Go Power 6-petal reed block? A Tilly HL bolts on directly. They originally came with a early flatback carb?
> 
> Who makes this V4 sloper that I have coming? Is that a Gem product?



Anyone able to shed light on these intakes?


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## leeha (Nov 11, 2011)

I don't know much about these intakes.
The V6 should be an interesting one.
Mine has a V4 intake that has REED cast
into it. I believe thats who made it.
There were a bunch of companies making 
intakes for these Mac's back in the day.
I would hit the kart forums for better info.



Lee


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## Jacob J. (Nov 11, 2011)

The Reed 458 sloper manifold uses the Pyramid reed cage, with either 4 or 6 reeds. A Tillotson HL carburetor bolts directly onto the Reed 458. Reed Engineering made a lot of parts for Mac and West Bend- intakes, exhaust headers, mufflers, transfer covers, etc. 

The V-4 sloper was made by McCulloch itself, Reed Engineering made one, and GEM made one. I've seen them all advertised in my old Karting World magazines. 
As with most things, the factory Mac part is the best.

There was also an aftermarket company called Mac Engineering which I don't believe was a part of McCulloch, but rather a stand alone mom and pop company. They made V-12 and V-16 manifolds. I have a flat-top Mac Engineering V-16 manifold. 

GEM also made the V-6 manifold in a traditional style intake and stuffer intake. They made the most popular dual-carb manifold which is a traditional V-12. 

Hovey Engineering made a traditional "goose-neck" V-6 manifold for the early 9-port blocks, like the Mc-6 through Mc-9.


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## cpr (Nov 11, 2011)

cpr said:


> I started working on mine, get rwoods going and 4 of us are doing it. Another AS build-off, lol?



Tried to rep you JJ. Your wealth of knowledge continues.


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## blsnelling (Nov 11, 2011)

Thanks Jacob.


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## Jacob J. (Nov 11, 2011)

blsnelling said:


> Thanks Jacob.



I'll try to get pictures of these manifolds up this weekend in this thread. I have one each of most of them. Like Lee mentioned, the possibilities with these old Mac engines are far and wide and between porting, piston configuration, and intake/exhaust- a guy can tune these motors to do just about anything.


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## blsnelling (Nov 11, 2011)

Jacob J. said:


> I'll try to get pictures of these manifolds up this weekend in this thread. I have one each of most of them. Like Lee mentioned, the possibilities with these old Mac engines are far and wide and between porting, piston configuration, and intake/exhaust- a guy can tune these motors to do just about anything.



Pics would be awesome


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## NORMZILLA44 (Nov 12, 2011)

Good thread, good old Kart engine Very interesting stuff as well.


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## RiverRat2 (Nov 12, 2011)

Jacob J. said:


> You can do up a SP-125 first. I still have one here with your name on it.



Hey Put me on that list for the next one,,, and if will sneezes,,, I'll snake him on it!!!!

Did you ever find me a unlimited coil for the new 390 XP???

and a 390 muffler,,, It seems my hotrod had a little accident!!!

Nice saws Brad,,,,, I'm suscribing!!!!


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## blsnelling (Nov 12, 2011)

What's this about a coil and a muffler? What are you needing?


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## MechanicMatt (Nov 12, 2011)

Brad, Ive been fallowing along on your thread. Thanks to you there were four yellow saws in my dreams last night. I gotta unsubscribe before I catch a fever.


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## ausneil 1 (Nov 12, 2011)

MechanicMatt said:


> Brad, Ive been fallowing along on your thread. Thanks to you there were four yellow saws in my dreams last night. I gotta unsubscribe before I catch a fever.






Haha, its not hard mate, its good to see others still like playing with the old girls.
I'm following this thread also.


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## RiverRat2 (Nov 12, 2011)

blsnelling said:


> What's this about a coil and a muffler? What are you needing?



Sorry Brad,,,

I didnt mean to Hijack your thread i was trying to catch JJ but he had already bugged out,,,,
nice looking Macs you have there,,,

My 390XP hotrod took an unexpected ride off of the stump with a rather large yellow pine driving last week when I accidently cut through one side of the hinge on the back cut,,, kind of gave the muffler a rather smushed faced look,,, but I got lucky besides a few scratches thats about all that happened,,,

on the parts,,,

and I was hunting a used 390 muffler for my older saw and an unlimited Husky coil for my new 390XP I bought from Spike right after you started the Monster _390XP_ thread,,,, talk about yellow fever,,,, I think I'm coming down with something too!!!!

Ya,,, My CAD,,, it's BAD!!!! :biggrin:



ausneil 1 said:


> Haha, its not hard mate, its good to see others still like playing with the old girls.
> I'm following this thread also.



That's what I'm thinkin!!!!


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## blsnelling (Nov 12, 2011)

RiverRat2 said:


> Sorry Brad,,,
> 
> I didnt mean to Hijack your thread i was trying to catch JJ but he had already bugged out,,,,
> nice looking Macs you have there,,,
> ...



I believe I've got a muffler for you if you still need one. Let me know.


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## Jacob J. (Nov 12, 2011)

blsnelling said:


> I believe I've got a muffler for you if you still need one. Let me know.



I'm working on both the coil and the muffler for Rick. I already got him a set of dawgs.


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## RiverRat2 (Nov 12, 2011)

blsnelling said:


> I believe I've got a muffler for you if you still need one. Let me know.



Thanks Brad,,, I will get back to you when I have had time to really look at it a bit better tomorrow after church,,,,,, I cant wait to see how those Macs turn out,,,, 

I was working on shop stuff all day today and didnt really have time to throw it up on the bench an have a good look @ it,,,

On a lighter note,,, I did luck up on a good low hr Stihl FS 120 brush cutter that we took in on trade today,,, the muffler still has the white heat paint splotch on it  the guy said it had not run in the last year or two and it was just too heavy,,,,, he wanted a new 4 stroke Kombi with a ton of attachments,,, I think they gave him $60.00 trade in,,, ,,, 


I opened the fuel cap,,, and it looked like premix syrup,,,,, I flushed/drained it a few times with fresh Ultra Mix,,, primed it for about ten cycles to flush the carb a bit choked it and it started on the second pull,, I got it off choke while still running on fast start and it took off!!!! blipped the throttle and it purred like a kitten!!!! couldnt believe it,,,,


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## RiverRat2 (Nov 12, 2011)

Jacob J. said:


> I'm working on both the coil and the muffler for Rick. I already got him a set of dawgs.



You are the man Jacob,,,,,,


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## blsnelling (Nov 13, 2011)

I know you're a busy man Jacob, but I'd love to see pics of those different intakes!


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## blsnelling (Nov 14, 2011)

I hope to get started on these tomorrow night. I've got my other projects done. Time for my stuff I mailed the 101 block off to Terry Ives today. Hopefully I'll get good news in a few days.


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## blsnelling (Nov 14, 2011)

Just landed another nice piece for my kart saw. Picked up a nice 36" roller nose B&C from the Saw-King. This might be my first purchase from him. I've looked at a lot of his stuff, but never landed a deal with him. So, which one of you bumped the price $65 in the last 3 seconds?


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## leeha (Nov 14, 2011)

blsnelling said:


> Just landed another nice piece for my kart saw. Picked up a nice 36" roller nose B&C from the Saw-King. This might be my first purchase from him. I've looked at a lot of his stuff, but never landed a deal with him. So, which one of you bumped the price $65 in the last 3 seconds?



Weren't me, he's got me blocked.:msp_sneaky:
But 65 beans for a B+C ain't to bad if the roller is good.

Looks like a got a 101AA coming my way. 
Another thread will be started.



Lee


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## RiverRat2 (Nov 14, 2011)

blsnelling said:


> Just landed another nice piece for my kart saw. Picked up a nice 36" roller nose B&C from the Saw-King. This might be my first purchase from him. I've looked at a lot of his stuff, but never landed a deal with him. So, which one of you bumped the price $65 in the last 3 seconds?



post up the link so we can see it!!!!


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## turtle561 (Nov 14, 2011)

The chainsaw guy shop talk McCulloch Super Pro 125 36 inch bar chain 10 11 - YouTube


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## parrisw (Nov 15, 2011)

leeha said:


> Weren't me, he's got me blocked.:msp_sneaky:
> 
> Lee



Were you a bad boy Lee?


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## leeha (Nov 15, 2011)

parrisw said:


> Were you a bad boy Lee?



I'm never a bad boy, He just screwed me royally
so i left him a big NEG. This was years ago on a
Johnny 111S.




Lee


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## Ambull (Nov 15, 2011)

That bar went for $130, not $65. Sweet roller nose though, and a brand new chain with it.

eBay - New & used electronics, cars, apparel, collectibles, sporting goods & more at low prices


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## turtle561 (Nov 15, 2011)

be glad it wasn't this one. he'll put new skip tooth on just about anything.lol

Vintage Mcculloch Chainsaw 36" Roller Tip Bar with new chain | eBay


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## blsnelling (Nov 15, 2011)

I've got a real weak spot for roller nose bars. I definately wanted one for this build.


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## Jacob J. (Nov 15, 2011)

Those old external roller bars are good for displays saws and if you want to make a few cuts every once in a while. If you were going to cut logs or mill all day though, you'd want a modern sprocket nose bar.


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## cpr (Nov 15, 2011)

turtle561 said:


> be glad it wasn't this one. he'll put new skip tooth on just about anything.lol
> 
> Vintage Mcculloch Chainsaw 36" Roller Tip Bar with new chain | eBay



I bought that one. Rails were repaired, good job on that. Couple minutes with the sander, good as new. Roller's nice and came with full comp.


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## ale (Nov 15, 2011)

That roller nose will look sweet for this build.

...Brad are you a triplet and does one brother work full time, the other post on AS all day and you build saws full time? Fess up man, where do you make the time?


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## 7oaks (Nov 15, 2011)

ale said:


> That roller nose will look sweet for this build.
> 
> ...Brad are you a triplet and does one brother work full time, the other post on AS all day and you build saws full time? Fess up man, where do you make the time?



My thinking exactly. I spent all day working on one saw and didn't get much done and now I'll spend the rest of the evening uploading pics. Brad, you have my respect!


----------



## jra1100 (Nov 15, 2011)

Really looking forward to this build. Lots of pics and video I hope. Perhaps this will get me off my azz and work on my SP. I'm surprised that Mark hasn't replied to this one. JR


----------



## parrisw (Nov 15, 2011)

leeha said:


> I'm never a bad boy, He just screwed me royally
> so i left him a big NEG. This was years ago on a
> Johnny 111S.
> 
> ...



Ouch, that sucks.


----------



## heimannm (Nov 15, 2011)

He's watching...


----------



## RandyMac (Nov 15, 2011)

wire brushed rollers are cool, trippy to watch.

JJ is correct rollers won't take abuse for long, I loosened many making plunge cuts while bucking.


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## blsnelling (Nov 15, 2011)

Herb tried to call me tonight and I was in the garage and missed the call My block should be at Terry Ives tomorrow or Thursday.


----------



## RiverRat2 (Nov 16, 2011)

blsnelling said:


> That's all the pics for now.



What constitutes a Kart Motor???? Is there a CC/displacement level,,, like 100CC's???? or is it two piece block/head config or what??

would an I-41 mac be called considered a kart motor???? what size are they????


----------



## wyk (Nov 16, 2011)

RiverRat2 said:


> What constitutes a Kart Motor???? Is there a CC/displacement level,,, like 100CC's???? or is it two piece block/head config or what??
> 
> would an I-41 mac be called considered a kart motor???? what size are they????



Kart racing - Wikipedia, the free encyclopedia

_The first kart manufacturer was an American company, Go Kart Manufacturing Co. (1958). McCulloch was the first company, in 1959, to produce engines for karts. Its first engine, the McCulloch MC-10,[5] was an adapted chainsaw 2-stroke engine.[6] Later, in the 1960s, motorcycle engines were also adapted for kart use, before dedicated manufacturers, especially in Italy (IAME), started to build engines for the sport._


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## heimannm (Nov 16, 2011)

Kart engines were built specifically for go-kart racing. In many cases the block was the same casting at the chain saw engine, but porting was different and the kart engines are generally much higher output than the equivalent saw engine. There were other variations in the machining as some features required for a saw were not machined for the kart and vise versa.

The McCulloch kart engines ranged from around 80 cc's up to 123 cc's.

The 1-41 with removable head was very similar to the MAC10 engine, but with less aggressive porting to provide a long service life. The D-44, Super 44, and Super 44A were closer to the kart engines, later saws were de-tuned somewhat to increase longevity.

Mark


----------



## Brian13 (Nov 16, 2011)

RiverRat2 said:


> What constitutes a Kart Motor???? Is there a CC/displacement level,,, like 100CC's???? or is it two piece block/head config or what??
> 
> would an I-41 mac be called considered a kart motor???? what size are they????



Many of the kart and saw engines were loosely based off of each other. There were karts that had one piece heads, and saw engines with 2 piece heads. It was porting that set apart kart from saw engines. The kart engines generally were geared to higher revs if I understand it right.

You beat me to it Mark.


----------



## RiverRat2 (Nov 16, 2011)

heimannm said:


> Kart engines were built specifically for go-kart racing. In many cases the block was the same casting at the chain saw engine, but porting was different and the kart engines are generally much higher output than the equivalent saw engine. There were other variations in the machining as some features required for a saw were not machined for the kart and vise versa.
> 
> The McCulloch kart engines ranged from around 80 cc's up to 123 cc's.
> 
> ...



So how many CC's is the I-41 around 80??? and would it be considered a kart engine if it has a two piece Head/Block??? 

I helped my brother when he raced karts back in the late 70's earlyt 80's but they were all one piece head/block 100CC piston ported yamaha engines and yes it seems there were some Italian motors,,, Arghhhh that time in my life was kind of hard on the memory banks and a bit vague,,, errrr,,,, cloudy/smokey/hazy,,, if you know what I mean????? 

Sorry about all the questions,,, I think I may have been bitten by a yellow/black Bug....


----------



## heimannm (Nov 16, 2011)

As noted, the 1-40 and 1-41 with removable heads were developed from the same castings as the kart engines, but the porting and compression were designed to provide lower output and a longer service life.

The 1-40 saws were all 80 cc/4.9 In³.

Not all removeable head engines were necessarily kart engines, they just came from the same parents.

Mark


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## Brian13 (Nov 16, 2011)

The 1-41 is a 80cc saw engine. The 2-piece head has no bearing on whether or not its a kart engine. Its the porting that separates the two. The saw engines I believe would be more geared toward torque, and a kart more toward higher revs.


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## cpr (Nov 16, 2011)

And on the early ones (MC-10), the heads were different, too.


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## Ambull (Nov 16, 2011)

Here is a pretty good reference for Kart engines:

McCulloch Engine Identification

And McBob's website has a fairly comprehensive listing of McCulloch motors.

http://macbobaust.com/bores.html


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## nmurph (Nov 16, 2011)

Nope, a kart engine is any old chainsaw sold on Ebay.


----------



## RiverRat2 (Nov 16, 2011)

nmurph said:


> Nope, a kart engine is any old chainsaw sold on Ebay.



Yeah,,, I'm beginning to see that!!!!! especdially if it is a yellow or yellow and black one!!!!!


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## Dennis Cahoon (Nov 16, 2011)

Hey Lee, will this old Mac 101AA be good enough for that magic paint of yours??????......Don't tell Smelling what you payed for it.......Hahahahahahahaha!


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## blsnelling (Nov 16, 2011)

I bought another block tonight. Anyone have a line on a piston a little more than .070" over? It has a clean bore, but no piston.


----------



## Dennis Cahoon (Nov 16, 2011)

blsnelling said:


> I bought another block tonight. Anyone have a line on a piston a little more than .070" over? It has a clean bore, but no piston.



Lee won't need a piston with this one Brad.......just move compression release, add parts and paint!.......Yeeeeeehaaaaaa!


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## Ambull (Nov 17, 2011)

[video=youtube;e7z_ztMxBgk]http://www.youtube.com/watch?v=e7z_ztMxBgk[/video]


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## Brian13 (Nov 17, 2011)

Dennis Cahoon said:


> Hey Lee, will this old Mac 101AA be good enough for that magic paint of yours??????......Don't tell Smelling what you payed for it.......Hahahahahahahaha!



Nice looking motor!! Sounds like its going into good hands.

Been wanting a 101 for awhile to play with, just havnt had the funds. You guys are making me jealous with all these 101 builds:msp_tongue:.


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## little possum (Nov 17, 2011)

Im not jealous Brian. I am hoping 125, 797, 895 prices will come down


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## Brian13 (Nov 17, 2011)

little possum said:


> Im not jealous Brian. I am hoping 125, 797, 895 prices will come down



LOL, I am jealous and hoping the prices will come down.


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## Dennis Cahoon (Nov 17, 2011)

Sorry boy's......the 125's and 101's I have left are getting like gold.......and going up as we speak!......but at least they have good pistons........Hahahahahahaha!


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## Dennis Cahoon (Nov 17, 2011)

Looks like this 125c's headed to Texas!


----------



## Jacob J. (Nov 17, 2011)

I decided to scan a great article from the old Karting World magazine on porting of the Mac kart blocks. This is kind of a long-winded article but has some great, great info on porting these blocks. I highly recommend anyone who intends on modifying one of these to read this.

View attachment 207559
View attachment 207560


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## cpr (Nov 17, 2011)

Keep running it up! The sooner the better. I'll sell the lot and be tractor pulling in the spring :hmm3grin2orange:.


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## Jacob J. (Nov 17, 2011)

Jim Butler is the grandfather of Mac engine building and was probably the most knowledgeable kart engine enthusiast ever.

View attachment 207561
View attachment 207562


----------



## Jacob J. (Nov 17, 2011)

View attachment 207563


----------



## Ambull (Nov 17, 2011)

Jacob J. said:


> I decided to scan a great article from the old Karting World magazine on porting of the Mac kart blocks. This is kind of a long-winded article but has some great, great info on porting these blocks. I highly recommend anyone who intends on modifying one of these to read this.
> 
> View attachment 207559
> View attachment 207560



You are missing the middle two pages. Actually they are probably here on one of these posts somewhere.


----------



## Jacob J. (Nov 17, 2011)

Ambull said:


> You are missing the middle two pages. Actually they are probably here on one of these posts somewhere.



View attachment 207566


----------



## boda65 (Nov 17, 2011)

Jacob J. said:


> Jim Butler is the grandfather of Mac engine building and was probably the most knowledgeable kart engine enthusiast ever.




That $100 price tag is appealing, but adjusted for inflation equals $720 in 2010 dollars. I too am drooling over all these kart engine builds. I know how my SP105 runs, I can only imagine how a SP125 or 101 equipped saw would feel. Yee Ha!


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## ausneil 1 (Nov 17, 2011)

Dennis Cahoon said:


> Lee won't need a piston with this one Brad.......just move compression release, add parts and paint!.......Yeeeeeehaaaaaa!




Is that where the decom normaly is, havn't seen one up there. 
Then again i no nothing about kart engines.


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## cpr (Nov 17, 2011)

No, not from the factory. I've seen a few with one drilled there, though.


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## blsnelling (Nov 17, 2011)

Anyone ever seen a dual carb setup on a V4 sloper?


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## cpr (Nov 17, 2011)

That's different. Never seen one on a sloper or oreintated that way...


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## blsnelling (Nov 17, 2011)

I wouldn't think a V4 would flow enough for dual carbs.


----------



## leeha (Nov 17, 2011)

I have never seen an intake like that either.
Strange set up.

Jacob, Nice info you provided. Thanks




Lee


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## blsnelling (Nov 17, 2011)

Just seems to me, that if you want to run dual carbs, you'd want a V8, V12, or V16.


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## blsnelling (Nov 17, 2011)

Jacob, thanks for the article.


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## Freehand (Nov 18, 2011)

Real good stuff JJ,thanks.


http://www.arboristsite.com/attachments/chainsaw/207559d1321547668-mc-6-1-gif
http://www.arboristsite.com/attachments/chainsaw/207566d1321549719-mc-6-6-gif
http://www.arboristsite.com/attachments/chainsaw/207560d1321547719-mc-6-2-gif
http://www.arboristsite.com/attachments/chainsaw/207561d1321547893-mc-6-3-gif
http://www.arboristsite.com/attachments/chainsaw/207562d1321547947-mc-6-4-gif
http://www.arboristsite.com/attachments/chainsaw/207563d1321548089-mc-6-5-gif


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## Arrowhead (Nov 18, 2011)

Awesome info getting posted here! 

I got yellow fever now, just need to save up a little more green.


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## Jacob J. (Nov 18, 2011)

blsnelling said:


> Just seems to me, that if you want to run dual carbs, you'd want a V8, V12, or V16.



Yeah, you need the reed area of at least 8 standard Mac reeds to take advantage of the flow characteristics that dual HL carbs can provide. Jim Butler did an article (which I'll try to find) where he flow-tested the common 4-6, 8, 12, and 16 reed manifolds and found that only 8 and above provided the CFM necessary to take advantage of twin HL-187a carbs. The 187a was an early HL performance carb which could be tuned to run either gas or methanol and it's a lower performance carburetor than the current 300-series carbs available today. 



Freehand said:


> Real good stuff JJ,thanks.



There's a reason I didn't embed those pictures. They're quite large and some of the people interested in this thread are still on dial-up.


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## Freehand (Nov 18, 2011)

Sorry JJ,just attempting to put them in order.Dial-up guys: It's worth the wait.


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## Dennis Cahoon (Nov 18, 2011)

blsnelling said:


> Anyone ever seen a dual carb setup on a V4 sloper?




Here's a portion of my manifolds......but looks like the slopers are straight, one dual and one single. I like the V-12 reed with the a big single burris mikuni or the twin tillitsons. The twin set-up can be alittle harder to tune. These are 4-sale.....with Leeha and RiverRat getting first choice......Don't even ask Brad!.......Hahahahahahaha!


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## little possum (Nov 18, 2011)

Uncle Dennis, Ill take the ugliest, slowest, piece you can make run


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## blsnelling (Nov 18, 2011)

Dennis Cahoon said:


> Here's a portion of my manifolds......but looks like the slopers are straight, one dual and one single. I like the V-12 reed with the a big single burris mikuni or the twin tillitsons. The twin set-up can be alittle harder to tune. These are 4-sale.....with Leeha and RiverRat getting first choice......Don't even ask Brad!.......Hahahahahahaha!



Sweet assortment of manifolds there, Dennis. I don't see anything there I can use though. Keep trying


----------



## MechanicMatt (Nov 19, 2011)

Dennis, that is a very impressive collection you got there. I have one question, Im fairly new to this site and am wondering, What is up with all the HAHAHAHAHHAHA? Is that like your calling card, kinda like "gigidy gigidy" or "I pity the fool" or WAIT I GOT IT, woody wood pecker, thats it! Right your copying Woody Wood Pecker? I loved that cartoon. You do have a nice collection of McCulloch speed there, I really like the dual carb setup. Kinda reminds me of a tunnel ram with two double pumper 750's on it. Looks mean just sitting there!


----------



## Eccentric (Nov 19, 2011)

MechanicMatt said:


> Dennis, that is a very impressive collection you got there. I have one question, Im fairly new to this site and am wondering, What is up with all the HAHAHAHAHHAHA? Is that like your calling card, kinda like "gigidy gigidy" or "I pity the fool" or WAIT I GOT IT, woody wood pecker, thats it! Right your copying Woody Wood Pecker? I loved that cartoon. You do have a nice collection of McCulloch speed there, I really like the dual carb setup. Kinda reminds me of a tunnel ram with two double pumper 750's on it. Looks mean just sitting there!



My guess is that it's an inside joke between Dennins and Brad....


----------



## ausneil 1 (Nov 20, 2011)

Dennis Cahoon said:


> Here's a portion of my manifolds......but looks like the slopers are straight, one dual and one single. I like the V-12 reed with the a big single burris mikuni or the twin tillitsons. The twin set-up can be alittle harder to tune. These are 4-sale.....with Leeha and RiverRat getting first choice......Don't even ask Brad!.......Hahahahahahaha!




Dennis,, that BDC up the back, by chance is it a alky carby and if it is would it be any good to a working class aussie like me, I'm realizing of coarse others get first pic.


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## blsnelling (Nov 20, 2011)

Eccentric said:


> My guess is that it's an inside joke between Dennins and Brad....



Nope.


----------



## youngs24 (Nov 20, 2011)

Dennis Cahoon said:


> Here's a portion of my manifolds......but looks like the slopers are straight, one dual and one single. I like the V-12 reed with the a big single burris mikuni or the twin tillitsons. The twin set-up can be alittle harder to tune. These are 4-sale.....with Leeha and RiverRat getting first choice......Don't even ask Brad!.......Hahahahahahaha!



come on dennis you have got to have one of the manifold that goes in place of the stuffer for a 4 carb set up where's it at? Thanks Troy!


----------



## blsnelling (Nov 21, 2011)

I just talked to Terry Ives and got an excellent report. The block is good. He believes that .060" will clean it up. Also the exhaust port is standard height. It's just been filed on and needs cleaned up!


----------



## parrisw (Nov 21, 2011)

blsnelling said:


> I just talked to Terry Ives and got an excellent report. The block is good. He believes that .060" will clean it up. Also the exhaust port is standard height. It's just been filed on and needs cleaned up!



Good news!! Good to hear.


----------



## Dennis Cahoon (Nov 21, 2011)

ausneil 1 said:


> Dennis,, that BDC up the back, by chance is it a alky carby and if it is would it be any good to a working class aussie like me, I'm realizing of coarse others get first pic.



Neil, have several of those BDC's. Haven't looked to see if they're drilled for alkie or not. If you need them, let me know. Later Dennis


----------



## ausneil 1 (Nov 21, 2011)

Dennis Cahoon said:


> Neil, have several of those BDC's. Haven't looked to see if they're drill for alkie or not. If you need them, let me know. Later Dennis




thankyou.


----------



## blsnelling (Nov 21, 2011)

I also learned that this block has already been in a chainsaw, so the conversion work has already been done

Do I need a 101 stuffer, or can I use the one off the SP125C?

Herb told me this afternoon that someone's selling GEM like mufflers without the name on them. Anyone have a source for them?


----------



## cpr (Nov 21, 2011)

The gusseted 101 stuffers won't work. Easiest to use a 125 stuffer so you don't have to drill the ao impulse port. The shape of them is the same anyway.


----------



## blsnelling (Nov 21, 2011)

cpr said:


> The gusseted 101 stuffers won't work. Easiest to use a 125 stuffer so you don't have to drill the ao impulse port. The shape of them is the same anyway.



More good news. Thanks mang.


----------



## blsnelling (Nov 22, 2011)

I finally got around to tearing down this other SP125C that already had a 101 block in it. It had no compression and rattled when you pulled it over. I was told this saw ran and had great compression at one point. What I found is nothing short of amazing. The piston is .020" smaller than the bore! The rings are actually smaller than the piston! Three of the six head bolts were stripped out with no threads in them at all. How this thing could have possibly run is beyond me! 

This .030" over piston I have is .010" bigger than the bore. It looks like an over bore of about .016" will make a nice fit for this piston.

*What should be done with the rod bolts? Can they be tapped to a larger size, or should I put in steel inserts? I noticed that the threads are way receded on the three good holes. Is that necessary, or can they just be sufficiently below the surface so as to not affect head sealing?*

Bore - 2.295"
Piston - 2.2715" bottom skirt, 2.2745" just below ring. Yes, smaller at the skirt.


----------



## blsnelling (Nov 22, 2011)

blsnelling said:


>



Interestingly enough, the bore on my block, the one with Terry Ives, is the same. I'm thinking now that I can use that piston in this block. The bore is beautiful in this one that I'm working on.


----------



## leeha (Nov 22, 2011)

*What should be done with the rod bolts? Can they be tapped to a larger size, or should I put in steel inserts? I noticed that the threads are way receded on the three good holes. Is that necessary, or can they just be sufficiently below the surface so as to not affect head sealing.[/QUOTE]


Are you talking rod bolts or head bolts.
If rod bolts, Throw them away as well as the rod
if there damaged in anyway. If your talking head
bolts. Buy new bolts and the nuts they thread into.
The head bolts do not thread into the block itself.



Lee*


----------



## blsnelling (Nov 22, 2011)

Anyone have SKF or similiar seal PNs for these saws? How about the crank bearings?


----------



## blsnelling (Nov 22, 2011)

leeha said:


> Are you talking rod bolts or head bolts.
> If rod bolts, Throw them away as well as the rod
> if there damaged in anyway. If your talking head
> bolts. Buy new bolts and the nuts they thread into.
> ...



You're right. I meant head bolts. I did have a few extra nuts laying around, lol. Guess I know where they go now. My isn't it fun learning a new engine I will be using new rod bolts.

Edit: I just went and looked. I see where three of the nuts are held in with clips, and three just slide into a recess. Those had fallen out.


----------



## Jacob J. (Nov 22, 2011)

blsnelling said:


> Anyone have SKF or similiar seal PNs for these saws? How about the crank bearings?



6620 is the SKF seal for the Flywheel side. Lee can correct me if I'm wrong but I believe 6203s are the bearings for both sides on the 125.

I can't remember the PTO side seal in SKF.


----------



## blsnelling (Nov 22, 2011)

Jacob J. said:


> 6620 is the SKF seal for the Flywheel side. Lee can correct me if I'm wrong but I believe 6203s are the bearings for both sides on the 125.
> 
> I can't remember the PTO side seal in SKF.



Thanks Jacob. Good ole 6203 huh? That's easy enough. Do they need to be C3?


----------



## rupedoggy (Nov 22, 2011)

Brad you are dealing with the best man I know for Mc Karts. If you have problems, questions, etc. ask Terry Ives. He is one of the premier builders and has the answers and parts for Karts right at his fingertips. He KNOWS!


----------



## Jacob J. (Nov 22, 2011)

blsnelling said:


> Thanks Jacob. Good ole 6203 huh? That's easy enough. Do they need to be C3?



I've been using the 6203 Z rated EM bearings because they have a higher RPM rating, but C3s are fine.


----------



## leeha (Nov 23, 2011)

And if you happen to get 6203 bearings with the
seals in them, You can just pop the seals out.
All the crank seals i have been getting are oem.
Bobs Lawnmower, Discount marine, or vintage vixon
on ebay had a bunch. There will be 3 seals, all
different.




Lee


----------



## Brian13 (Nov 23, 2011)

Cpr had a saw like that as well where there was a piston that was significantly smaller than the bore. Is it possible that was done on purpose? Dont see where that would seem like a good plan.


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## blsnelling (Nov 23, 2011)

I honestly thought I'd been setup with a "test" by the owner of this saw


----------



## Eccentric (Nov 23, 2011)

blsnelling said:


> I honestly thought I'd been setup with a "test" by the owner of this saw



Don't worry about it Brad.......................you passed!


----------



## blsnelling (Nov 23, 2011)

Eccentric said:


> Don't worry about it Brad.......................you passed!



It doesn't run yet!


----------



## gink595 (Nov 23, 2011)

Brad, I think this is the longest on going build you've ever had! I bet your getting anxious!!


----------



## Dennis Cahoon (Nov 23, 2011)

Eccentric said:


> Don't worry about it Brad.......................you passed!



Ah!.....the good ole test for dummies!......Hahahahahahaha!


----------



## blsnelling (Nov 23, 2011)

gink595 said:


> Brad, I think this is the longest on going build you've ever had! I bet your getting anxious!!



Sure isn't like building a modern saw! I still don't have the sloper from northern Ohio, lol. I'm still waiting for him to tell me how much shipping is. He actually takes it down and has it weighed. Then I have to mail him a money order. Old school all the way


----------



## blsnelling (Nov 23, 2011)

Here's a MC 91 engine that arrived this week. This baby is nice. I would pull it down for a good cleaning before running it, but it looks to be in excellent condition. So, what should it go in, a 250 for some 44 variant? What makes for the cleanest conversion, AV, auto oiler, etc.?






















I had no idea these carbs were so big! I think this monster would fuel a SBC!










And here's a nice new handle for my 101 saw.


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## little possum (Nov 23, 2011)

Send it too me, Ill stick it in a hybrid of sorts. Then ship it directly back.

Worth a try anyways. I think a nice new paint job on a 250 with black top and the super lid, or drill ya some holes... Full wrap, and big dog. 30" roller nose.

Sounds perfect to me... 44s have a good look to them, that I almost prefer over the 250s


----------



## Brian13 (Nov 23, 2011)

Go with the 250, will be the easiest to build.
[video=youtube_share;cs8LoMhT6YQ]http://youtu.be/cs8LoMhT6YQ[/video]
[video=youtube_share;_zs3ta3xWR8]http://youtu.be/_zs3ta3xWR8[/video]


----------



## Eccentric (Nov 24, 2011)

blsnelling said:


> It doesn't run yet!



The test was whether or not you'd find the undersized parts....


----------



## blsnelling (Nov 30, 2011)

Finally! The 101 block should be headed back from Terry with the new piston, bearings, bolts, etc. The sloper should be headed this way today as well.


----------



## jra1100 (Nov 30, 2011)

blsnelling said:


> Finally! The 101 block should be headed back from Terry with the new piston, bearings, bolts, etc. The sloper should be headed this way today as well.



Glad that it's coming along. I hate to confess my ignorance, but no one else is willing, or they all already know, but what in tarnation is a sloper?


----------



## blsnelling (Nov 30, 2011)

Its a special intake that lays back at an angle instead of pointing straight up.


----------



## Ambull (Nov 30, 2011)

jra1100 said:


> Glad that it's coming along. I hate to confess my ignorance, but no one else is willing, or they all already know, but what in tarnation is a sloper?



Yes the regular Kart intakes will interfere with the tank, but supposedly the sloper will fit under the tank. The stock SP125 intake is small and it only has two reeds. The slopers are usually V4's, which means they have four reeds in a "V" formation. This type of reed setup greatly improves the flow.

The biggest intakes are V12's which take two carburetors. They interfere with the tank, so with this setup a custom tank can be built. Here is one that recently sold on Ebay:

eBay - New & used electronics, cars, apparel, collectibles, sporting goods & more at low prices

Here is an old Saw King video that shows a kart saw with a straight intake and a custom tank. Cuts pretty good.

[video=youtube;dhgurOBErqY]http://www.youtube.com/watch?v=dhgurOBErqY[/video]


----------



## Dennis Cahoon (Nov 30, 2011)

Wow!.....that V-12 sold for $139.......I better put a few on ebay.


----------



## blsnelling (Nov 30, 2011)

Dennis Cahoon said:


> Wow!.....that V-12 sold for $139.......I better put a few on ebay.



No doubt! AS really drives the price of parts up. All these 101 build threads and prices go through the roof. Definately a sellers market. BTW, I'm still looking for something like a Gem muffler if someone has one they'd sell.


----------



## Dennis Cahoon (Nov 30, 2011)

VINTAGE KART (GO CART) EXHAUST (MEGAPHONE STYLE) MUFFLER - FOR MCCULLOCH ENGINES | eBay


----------



## blsnelling (Nov 30, 2011)

Dennis Cahoon said:


> VINTAGE KART (GO CART) EXHAUST (MEGAPHONE STYLE) MUFFLER - FOR MCCULLOCH ENGINES | eBay


I've looked at those, but it would point straight back at the operator.


----------



## nmurph (Nov 30, 2011)

Ambull said:


> Here is an old Saw King video that shows a kart saw with a straight intake and a custom tank. Cuts pretty good.



That thing doesn't even sound like mac until it idles down when he is switching it off.


----------



## Jacob J. (Nov 30, 2011)

blsnelling said:


> I've looked at those, but it would point straight back at the operator.



Not only that, but those help narrow the powerband. If you want a wider torque range, then get the full boxed-in muffler or the round steel muffler.


----------



## cpr (Nov 30, 2011)

JJ, so I understand it, is that because the megaphone acts as the diffuser cone on a pipe, sucking exhaust out and charge in, but without the convergence cone to reflect the pressure wave that pushes the new charge back to the cumbustion chamber? Is this the net effect of raising the exhaust port relative to transfers "leaking" useful new charge before the compressing piston can close the port?


----------



## Ambull (Nov 30, 2011)

Dennis Cahoon said:


> Wow!.....that V-12 sold for $139.......I better put a few on ebay.



The same seller sold a siezed 101B for $750. Now that is a bit much......

eBay - New & used electronics, cars, apparel, collectibles, sporting goods & more at low prices


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## Jacob J. (Nov 30, 2011)

cpr said:


> JJ, so I understand it, is that because the megaphone acts as the diffuser cone on a pipe, sucking exhaust out and charge in, but without the convergence cone to reflect the pressure wave that pushes the new charge back to the cumbustion chamber? Is this the net effect of raising the exhaust port relative to transfers "leaking" useful new charge before the compressing piston can close the port?



Somewhat. It's a very crude diffuser in that sense. I don't think it's quite the same effect as raising the exhaust too high. I've never used one of those cones, but all the old-time kart guys that I trust have said that those cones make a narrow window of power and that they're only good high RPM and the motors have less torque, even with a stock block.



Ambull said:


> The same seller sold a siezed 101B for $750. Now that is a bit much......



I don't know what the hell is wrong with these people. Stock 101 parts are not that hard to find. McCulloch made literally millions of these engines.


----------



## blsnelling (Dec 1, 2011)

Merry Christmas to me, and thank you Dr Ives!

One new piston, new rings for both, new rod bolts, gaskets, seals, crank bearings, rod bearing needles, and head bolts.
















The remaining defects aren't high enough to be an issue and shouldn't affect performance at all. They're well below the top of the exhaust port. I'm sure glad I sent this block to Terry for a professional opnion before declaring it dead!





It only took .056" to clean it up.


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## blsnelling (Dec 1, 2011)

Here you can see the differences between my block and this other 101 saw I'm working on.






The exhaust was not raised as thought, just hacked on a little with a file. I'll clean it up before assembly.










You can see how much thinner the liner is on mine. One is .010" over and mine .056".


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## Brian13 (Dec 1, 2011)

Looks great!! Now get to work.


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## MechanicMatt (Dec 1, 2011)

Brad, My buddy I work for at night got a speed boat with a Big Block chevy 454 we punched it .030 on the last rebuild brought it up to 468 there is NO replacement for displacement, get that saw running already!


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## RTK (Dec 1, 2011)

Looks good Brad. By the way, does Mr Ives sell other parts for karting engines besides those being built for saws?


----------



## leeha (Dec 1, 2011)

Lookin good Brad. 
Looks like Terry took good care of ya.





Lee


----------



## RiverRat2 (Dec 1, 2011)

Looking really nice brad...



Jacob J. said:


> Somewhat. It's a very crude diffuser in that sense. I don't think it's quite the same effect as raising the exhaust too high. I've never used one of those cones, but all the old-time kart guys that I trust have said that those cones make a narrow window of power and that they're only good high RPM and the motors have less torque, even with a stock block.
> 
> 
> 
> I don't know what the hell is wrong with these people. Stock 101 parts are not that hard to find. McCulloch made literally millions of these engines.



Yeah that narrow power band was described by some of the oldtimers I Motocrossed with as (Pipey) that would make it a dog on lowend coming out of corners not very desirable,,, with a saw for racing I suppose it would require a very light hand and keep the RPM up to stay in the power band???


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## blsnelling (Dec 1, 2011)

RTK said:


> Looks good Brad. By the way, does Mr Ives sell other parts for karting engines besides those being built for saws?



I don't know what all Terry does. I've heard he's one of the best Mac builders in the country, but I don't know much more about him. Jacob could probably fill you in.


----------



## blsnelling (Dec 1, 2011)

MechanicMatt said:


> Brad, My buddy I work for at night got a speed boat with a Big Block chevy 454 we punched it .030 on the last rebuild brought it up to 468 there is NO replacement for displacement, get that saw running already!



I'll have to figure out what I've got now.

Bore 2.28" + .056" = 2.336"
Stroke = 1.835"

Displacement = 7.87 CI = 129cc


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## Dennis Cahoon (Dec 1, 2011)

RTK said:


> Looks good Brad. By the way, does Mr Ives sell other parts for karting engines besides those being built for saws?



Yes!.....He builds national winning kart engines.....new and old. He has had pistons made for the older 101 mac's and bores cylinders.


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## rupedoggy (Dec 1, 2011)

RTK said:


> Looks good Brad. By the way, does Mr Ives sell other parts for karting engines besides those being built for saws?



Terry Ives works on racing go karts. His love is racing karts and teaching others about them. He has tons of stuff. He only does the saws because they are the same as his vintage engines for the karts. I have been to his shop and he has been to my saw competitions but I think only to see the kart motors run and as a courtesy to us who have had him work on our stuff. He is a real old school gentleman and good to know. Mike


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## parrisw (Dec 2, 2011)

rupedoggy said:


> Terry Ives works on racing go karts. His love is racing karts and teaching others about them. He has tons of stuff. He only does the saws because they are the same as his vintage engines for the karts. I have been to his shop and he has been to my saw competitions but I think only to see the kart motors run and as a courtesy to us who have had him work on our stuff. He is a real old school gentleman and good to know. Mike



Sounds like a really good guy. Its a shame there are fewer and fewer of them around these days. Its pretty cool to hear that he enjoys sharing and teaching others about what he does, otherwise it would be lost forever.


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## Jacob J. (Dec 2, 2011)

There's a few of the kart good old boys around that are good engine builders. Terry of course is a legend, Vince Hughes down in Oceanside is another really good one. He's bored a couple of engines for me and does really amazing work. Another legendary character was Jimmy Yamane. He worked at McCulloch motors and was part of McCulloch's original kart engine design team. Jimmy had some pictures of one of his first karts that had two 790 chainsaw engines on it that he was beating the Homelites with.


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## Dennis Cahoon (Dec 2, 2011)

Another National winning kart builder is Dave Liberton, from Phoenix AZ. I bought 2 stock 101B's from him in the 90's that came off Israeli drones. I also bought his personal 101B that he won a national race with. He claimed it dyno'ed at 22hp.


----------



## RTK (Dec 2, 2011)

Thanks for the help and pointing me in the right direction guys


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## rwoods (Dec 2, 2011)

Dennis Cahoon said:


> Another National winning kart builder is Dave Liberton, from Phoenix AZ. I bought 2 stock 101B's from him in the 90's that came off Israeli drones. I also bought his personal 101B that he won a national race with. He claimed it dyno'ed at 22hp.



I would be thrilled to get 15hp from my toy saw. Can this be done with stock ports, gas and a kart muffler? I don't know what the stock rating of a 101B is, but some areo application charts listed them at 15hp - I would have thought 10. Ron


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## blsnelling (Dec 3, 2011)

More goodies showed up today.

















Are there better aftermarket reeds?










Is this a Mac part? I don't see any other markings on it.





Here's an adaptor block that will allow me to run a Tilly HL carb on it. I've not yet decided if I'm going to run an HL or the BDC.


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## cpr (Dec 3, 2011)

Looks good Brad. Wondering if that adapter will make the carb stick up too high to get the cover on though.


----------



## Jacob J. (Dec 3, 2011)

cpr said:


> Looks good Brad. Wondering if that adapter will make the carb stick up too high to get the cover on though.



He's not going to get the cover on anyway. He has to cut the air box area of the tank out for the sloper manifold and the stock mount wouldn't line up.


----------



## turtle561 (Dec 3, 2011)

*Fwiw*

boysen reeds ?
tuning tip from a kart site :Reed Cage Assembly








The last major development was a method of re- arching the reed guards. Our re-worked guards allowed the reeds to open at only a fraction of the force that it took to open them with the stock guards. The effect was amazing. The engines didn't sound anything like anyone else's as they had a deeper, throaty sound and they made so much more power we ended up all the way back to the 4 to 1 gear ratio everyone was running except we were still at 12,900 while the competition was at 11,200. The real neat thing about it was that the engines became ultra reliable once we sorted them out and I didn't have to run them lean or hot to get the power.


----------



## cpr (Dec 3, 2011)

I realize the box has to be cut. By alignment I assume you mean no bolt mount on the carb to receive the cover?


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## blsnelling (Dec 3, 2011)

turtle561 said:


> boysen reeds ?
> tuning tip from a kart site :Reed Cage Assembly
> 
> The last major development was a method of re- arching the reed guards. Our re-worked guards allowed the reeds to open at only a fraction of the force that it took to open them with the stock guards. The effect was amazing. The engines didn't sound anything like anyone else's as they had a deeper, throaty sound and they made so much more power we ended up all the way back to the 4 to 1 gear ratio everyone was running except we were still at 12,900 while the competition was at 11,200. The real neat thing about it was that the engines became ultra reliable once we sorted them out and I didn't have to run them lean or hot to get the power.



Thanks for the info! I'll definately do that mod to the reed stops. So Boysen reeds or from somewhere else is not recommended?


----------



## Busmech (Dec 3, 2011)

I think back when that may have been true, but modern reed materials are better. I've run both Mac and Boyeson and can't tell much difference.


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## Dennis Cahoon (Dec 3, 2011)

......V-force Tassinari make a modern version of the old mac 12 petal for pretty much everything now-a-day except for the Mac's. V-force are "kind".


----------



## turtle561 (Dec 3, 2011)

http://www.boyesen.com/-they are good, a current producer of reeds with modern materials and designs for performance cycles, outboards, karts, etc.
vintage karting sites may steer you to a source for vintage mac reeds. i think they were a fabric reinforced phenolic resin. there may be some made of modern stuff that matches the old mac flexibility ?
those old reeds would be 30 years old, so i'd look for some thing new. resins get brittle with age, as they are continually cureing.

http://www.ebay.com/itm/Genuine-McC...493?pt=LH_DefaultDomain_0&hash=item19cb4dd2d5


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## blsnelling (Dec 3, 2011)

Thanks guys! All info here is appreciated. I'm admittedly a newbie at all this and am trying to learn everything I can.

I finally nailed down a muffler.


----------



## cpr (Dec 3, 2011)

If you have a "b" block you might need the rectangle exhaust gasket to fit in the recess of the block. Was that the one on evilbay this week?


----------



## blsnelling (Dec 3, 2011)

cpr said:


> If you have a "b" block you might need the rectangle exhaust gasket to fit in the recess of the block. *Was that the one on evilbay this week?*



Yes.


----------



## Metals406 (Dec 3, 2011)

I'm even more newbeeish than Brad with reeds. . . So take my question for my experience -- but is there a reason the reeds can't be made from thin stainless?


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## cpr (Dec 3, 2011)

If a metal reed chips off, it'll trash the engine. The fiber ones won't.


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## Metals406 (Dec 3, 2011)

cpr said:


> If a metal reed chips off, it'll trash the engine. The fiber ones won't.



How would a guy chip a stainless reed?


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## Busmech (Dec 3, 2011)

Bang it against the reed block a few thousand times a minute, they'll split. Early saws had stainless reeds but they weren't high rpm motors. McCulloch and West Bend and others started building fast motors and switched to the phenolic reeds because they don't do damage when they fail.


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## Jacob J. (Dec 3, 2011)

turtle561 said:


> http://www.boyesen.com/-they are good, a current producer of reeds with modern materials and designs for performance cycles, outboards, karts, etc.
> vintage karting sites may steer you to a source for vintage mac reeds. i think they were a fabric reinforced phenolic resin. there may be some made of modern stuff that matches the old mac flexibility ?
> those old reeds would be 30 years old, so i'd look for some thing new. resins get brittle with age, as they are continually cureing.



Yeah I agree with passing on NOS Mac reeds unless it's just a shelf queen that you're going to run for short periods every once in a great while.

Some of the kart guys are switching to reinforced Carbon Fiber reeds which I've heard good things about. There's also some modern two-stage Boyesen reeds that fit the Mac cages. One group of the karters got together and had a batch of reeds made custom by Boyesen.


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## Dennis Cahoon (Dec 4, 2011)

blsnelling said:


> I finally nailed down a muffler.



Brad......that muffler doesn't even look like it belongs on a Mac chainsaw.......Put a round style muffler on it, at least make look like a Mac!


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## Dennis Cahoon (Dec 4, 2011)

This is the type of muffler people switched to from stock who really used these saws in the woods. That funky Gem muffler belongs on a go-kart and will degrade the look of the famous 101B.


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## blsnelling (Dec 4, 2011)

Dennis Cahoon said:


> Brad......that muffler doesn't even look like it belongs on a Mac chainsaw.......Put a round style muffler on it, at least make look like a Mac!





Dennis Cahoon said:


> This is the type of muffler people switched to from stock who really used these saws in the woods. That funky Gem muffler belongs on a go-kart and will degrade the look of the famous 101B.


Its that a Mac muffler or aftermarket?


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## MechanicMatt (Dec 4, 2011)

Brad, I don't know if it'll work good on your motor but my buddies all run carbon fiber reeds on there sleds. Oh SNOW MOBILES. Ive heard sleds called all different things. But you know what I mean. Good luck!!


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## Arrowhead (Dec 4, 2011)

Jacob J. said:


> Yeah I agree with passing on NOS Mac reeds unless it's just a shelf queen that you're going to run for short periods every once in a great while.
> 
> Some of the kart guys are switching to reinforced Carbon Fiber reeds which I've heard good things about. There's also some modern two-stage Boyesen reeds that fit the Mac cages. One group of the karters got together and had a batch of reeds made custom by Boyesen.



I run the 2 stage Boyesen reeds in my 6 cube Pioneers. They work awesome.


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## cpr (Dec 4, 2011)

blsnelling said:


> Its that a Mac muffler or aftermarket?



Mac. Came on a bunch of different saws.


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## rwoods (Dec 4, 2011)

Brad, to each his own. If you are trying to build a stock appearing 125 then you should use the 797 rectanglar muffler and a 125 muffler guard. if you are building a work saw, the round muffler is the way to go - much easier to replace the chain and you can adjust the direction of the exhaust. I have to be careful not to start a fire but this is what I am going to put on my kart saw except it will be painted black: 






Ron


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## blsnelling (Dec 4, 2011)

I think stock appearing is out of the question already with the intake and carb I'm going with. This will not be a work saw at all, just a GTG toy.


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## gink595 (Dec 4, 2011)

When I was into dirt bikes I had a CR250 I put the Boysen 2 stage reeds in and it made a huge difference in the power delivery. I remember at one track it was always questionable if I could get enough speed coming out of a corner to make a double jump, after I swapped those reeds out I never had that issue. The power came on alot quicker. I was sold after that.


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## blsnelling (Dec 4, 2011)

Does Boysen have a stock PN for the Mac reeds? Or, were these a special group buy by the kart guys? These reeds look ancient and I definately want to replace them.


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## Jacob J. (Dec 4, 2011)

blsnelling said:


> Does Boysen have a stock PN for the Mac reeds? Or, were these a special group buy by the kart guys? These reeds look ancient and I definately want to replace them.



It was a special buy. They bought 100 sets. I don't know if that was the minimum order or not.


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## Busmech (Dec 4, 2011)

Arrowhead said:


> I run the 2 stage Boyesen reeds in my 6 cube Pioneers. They work awesome.



Brad when I first started messing with 101s I contacted Boyesen about reeds, they had me trace a set of the v4 reeds with a sharp pencil and fax it too them. Turned out they had a set for a personal watercraft that matched perfectly, only difference was the size of the screw hole (had to be drilled larger). I will try to find the part # don't hold your breath tho it's been a long time. Also I prefer the GEM v4 reed block and reeds to the mac, I believe they flow better.


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## blsnelling (Dec 4, 2011)

Busmech said:


> Brad when I first started messing with 101s I contacted Boyesen about reeds, they had me trace a set of the v4 reeds with a sharp pencil and fax it too them. Turned out they had a set for a personal watercraft that matched perfectly, only difference was the size of the screw hole (had to be drilled larger). I will try to find the part # don't hold your breath tho it's been a long time. Also I prefer the GEM v4 reed block and reeds to the mac, I believe they flow better.



That would be awesome. Where they a 2-stage reed?


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## Busmech (Dec 4, 2011)

No they were just a flat reed.


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## Busmech (Dec 4, 2011)

Brad, check ebay item#110770597607 that is the GEM settup I referd to.


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## rwoods (Dec 4, 2011)

blsnelling said:


> I think stock appearing is out of the question already with the intake and carb I'm going with. This will not be a work saw at all, just a GTG toy.



With this thread everybody will know that your saw ain't stock but the man from down under's stock appearing saw is what got me started on gathering the parts. Unfortunately, I get outbid on every single pumper BDC that comes to my attention so I am going in a different direction as well. Ron


----------



## Busmech (Dec 4, 2011)

rwoods said:


> With this thread everybody will know that your saw ain't stock but the man from down under's stock appearing saw is what got me started on gathering the parts. Unfortunately, I get outbid on every single pumper BDC that comes to my attention so I am going in a different direction as well. Ron



Look for an HR tillotson, much more common than the bdc macs, parts are easier to find also.


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## Jacob J. (Dec 4, 2011)

Apart from the BDCs, there's some other good running large carbs out there, like the Tillotson HR and some of the bigger Mikuni diaphragm carbs.


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## blsnelling (Dec 4, 2011)

Busmech said:


> Brad, check ebay item#110770597607 that is the GEM settup I referd to.



That's a sweet deal for the price. I grabbed one while they're available. I'm still going to check into the Boysen 2-stage reeds though. Thanks for the heads up.


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## Ambull (Dec 5, 2011)

OK Brad, I put together a vid to show how I start a 101B Mac. This one is .050 over, 129cc, no decomp. It has fresh rings, and I notice the compression has been on the rise, as it is getting harder and harder to turn over. Not the best cut, as I realized the filter was dirty after I made the cut.

[video=youtube;imVCsFHAx-g]http://www.youtube.com/watch?v=imVCsFHAx-g&feature=youtube_gdata[/video]


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## cpr (Dec 5, 2011)

I love the exhaust blowing leaves on the ground around.


----------



## leeha (Dec 5, 2011)

Nice vid Ambull.
If i tried to start my 101's that way, I would
dislocate my arm. I ain't got the umph you got.




Lee


----------



## blsnelling (Dec 5, 2011)

Ambull said:


> OK Brad, I put together a vid to show how I start a 101B Mac. This one is .050 over, 129cc, no decomp. It has fresh rings, and I notice the compression has been on the rise, as it is getting harder and harder to turn over. Not the best cut, as I realized the filter was dirty after I made the cut.



You da man, drop starting 129cc of high compression kart motor


----------



## ozflea (Dec 5, 2011)

Just read this thread from start to finish hmmmmmmmmmmmmmmmmmmmmmm still got a way to go yet fellas !!!!!!!!!!!!!!!!!!!!!!!!

McBob 

Oh Cahoon that 101 cylinder you have with the decompressor drilled in from the side is factory came from a 101 M/C 

McBob.






















What looks like a stock 125c ......................


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## MechanicMatt (Dec 5, 2011)

Ambull, watching you find TDC reminded me of how I used to have to start my favorite FourWheeler. Honda 250R, bump that kick start to TDC than let her rip. Thats saw rips:msp_thumbup:


----------



## blsnelling (Dec 5, 2011)

ozflea said:


> Just read this thread from start to finish hmmmmmmmmmmmmmmmmmmmmmm still got a way to go yet fellas !!!!!!!!!!!!!!!!!!!!!!!!
> 
> McBob
> 
> ...



Hey McBob, thanks for stopping by


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## rwoods (Dec 5, 2011)

Brad, make sure you watch McBob's video. It is that thunder from downunder that inspired me to start gathering parts for a copycat build. Ron


----------



## cpr (Dec 5, 2011)

rwoods said:


> Brad, make sure you watch McBob's video. It is that thunder from downunder that inspired me to start gathering parts for a copycat build. Ron



Me, too. Coupled with getting the 91s, it derailed my first kartsaw build.


----------



## blsnelling (Dec 5, 2011)

I'll be building the other 125/101 before I build mine. I painted this part of the case tonight so that I can assemble the engine.


----------



## blsnelling (Dec 5, 2011)

I contacted Boyesen today about reeds for these saws. As mentioned earlier in the thread, they wanted a tracing. I figered a scaled scan would be even better. Here they are for anyone that needs this info.


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## ozflea (Dec 5, 2011)

Ignition on mine is electronic off a Ryobi whipper snipper no rev limiter and no points great and simple 

McBob.


----------



## rwoods (Dec 5, 2011)

ozflea said:


> Ignition on mine is electronic off a Ryobi whipper snipper no rev limiter and no points great and simple
> 
> McBob.



Thanks for the additional info. Except for an overbore my 101B block will be stock. I may add a DSP to the head. I haven't found a carb to fit in the cutout air box so I may be forced to depart from your design. I have a BDC16 and both a sloper and a straight intake. Ron


----------



## Ambull (Dec 5, 2011)

leeha said:


> Nice vid Ambull.
> If i tried to start my 101's that way, I would
> dislocate my arm. I ain't got the umph you got.
> 
> ...



Hey you ripped the cord right out of yours up in Maine..... At least it was the cord and not your shoulder.

These saws truly are "Tim the toolman Taylor" style.


----------



## ozflea (Dec 5, 2011)

rwoods said:


> Thanks for the additional info. Except for an overbore my 101B block will be stock. I may add a DSP to the head. I haven't found a carb to fit in the cutout air box so I may be forced to depart from your design. I have a BDC16 and both a sloper and a straight intake. Ron



The BDC 16 is an alkcy carb the BDC 14 a petrol carb with a single pump double on the 16 

McBob


----------



## Dennis Cahoon (Dec 6, 2011)

ozflea said:


> Just read this thread from start to finish hmmmmmmmmmmmmmmmmmmmmmm still got a way to go yet fellas !!!!!!!!!!!!!!!!!!!!!!!!
> 
> McBob
> 
> ...


----------



## husq2100 (Dec 6, 2011)

Dennis Cahoon said:


> Another National winning kart builder is Dave Liberton, from Phoenix AZ. I bought 2 stock 101B's from him in the 90's that came off Israeli drones. I also bought his personal 101B that he won a national race with. He claimed it dyno'ed at 22hp.



Dennis, at what RPM make 22hp the 101b does?????? :hmm3grin2orange:

hope the family and labs are well mate


----------



## blsnelling (Dec 6, 2011)

I'm looking for input for the color scheme on my saw. Correct me where I'm wrong, but weren't original colors a red rear shroud, blue flywheel cover, and black recoil? I'm a big fan of patriotic red/white/blue, and would like to throw some white in the mix somewhere. I like chrome too. I'm just not sure how to put it all together.


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## cpr (Dec 6, 2011)

The red/blue was the '76 centennial. The rest were typical mac color-of-the-day. Yellow, black, chrome. I think there were some white m's.


----------



## ozflea (Dec 6, 2011)

blsnelling said:


> I'm looking for input for the color scheme on my saw. Correct me where I'm wrong, but weren't original colors a red rear shroud, blue flywheel cover, and black recoil? I'm a big fan of patriotic red/white/blue, and would like to throw some white in the mix somewhere. I like chrome too. I'm just not sure how to put it all together.



Red cylinder shroud blue fan housing and blue starter housing and used a special decal of red white and blue i have them here for mine but i haven't seen any on ebay for ages.

Called American Racing Engines

I'll snap a pic of the sticker today if my batteries ain't flat and post it here.

McBob


----------



## rwoods (Dec 6, 2011)

*Colors*

Here's my first kart saw: 






Blue flywheel cover, Red shroud, Yellow crankcase cover. 

Here's my 101B for my build:






Red flywheel cover. Silver shroud, unpainted crankcase cover.

Ron


----------



## blsnelling (Dec 6, 2011)

I'm thinking red engine cover, white fan housing, blue recoil, chrome screen, a red or chrome oil tank, and maybe a blue or black clutch cover. I wish had the software to play with this visually. That would be pretty cool.

On a more technical note, how is the crankcase side cover sealed? I have a thin metal shim in the gasket kit that goes behind it, but it wouldn't give an air tight seal.


----------



## watsonr (Dec 6, 2011)

yamabond or any of the gasoline resistant stuff works. You said a thin shield goes between the case cover and the cylinder?


----------



## Chopwood (Dec 6, 2011)

To those who actually have experiance: how do these karts compare to the modern big saws? I'm talking about 3120's and 88's. Dennis, what is your opinion? I have run a few 166's 2100's,SP125 and an 056mag2. I think the modern saws are better. If I am wrong, let me know.


----------



## blsnelling (Dec 6, 2011)

watsonr said:


> yamabond or any of the gasoline resistant stuff works. You said a thin shield goes between the case cover and the cylinder?



I suspect it may be a shim used to set the endplay between crank bearings.

What are the two holes through the bore for the flywheel side crank seal?


----------



## RandyMac (Dec 6, 2011)

Chopwood said:


> To those who actually have experiance: how do these karts compare to the modern big saws? I'm talking about 3120's and 88's. Dennis, what is your opinion? I have run a few 166's 2100's,SP125 and an 056mag2. I think the modern saws are better. If I am wrong, let me know.



they would be left sulking in the weeds, slinking home looking over their shoulders.


----------



## ozflea (Dec 6, 2011)

Thats about it Randy ...................

McBob.


----------



## leeha (Dec 6, 2011)

blsnelling said:


> I'm thinking red engine cover, white fan housing, blue recoil, chrome screen, a red or chrome oil tank, and maybe a blue or black clutch cover. I wish had the software to play with this visually. That would be pretty cool.
> 
> On a more technical note, how is the crankcase side cover sealed? I have a thin metal shim in the gasket kit that goes behind it, but it wouldn't give an air tight seal.



If you find a place to chrome Magnesium, Please let me know.
As far as i know it can't be done. All the chrome on the Mac
kart engines is over aluminum. If you notice the chrome flywheel
housing is much heavier than a painted one off a saw as well as
the block side cover. So i don't think you can chrome the oil tank.
But it sure would look good.

As for the shim, I have no idea. Mine did not have any shims.
I would call Terry on that one.



Lee


----------



## leeha (Dec 6, 2011)

RandyMac said:


> they would be left sulking in the weeds, slinking home looking over their shoulders.



Nuff said!!!!!!!!!!!!!!!!!!!!



Lee


----------



## ozflea (Dec 6, 2011)

McCulloch Racing Engine sticker onm a 101 M/C see the decompressor Dennis







McBob.


----------



## Ambull (Dec 6, 2011)

Chopwood said:


> To those who actually have experiance: how do these karts compare to the modern big saws? I'm talking about 3120's and 88's. Dennis, what is your opinion? I have run a few 166's 2100's,SP125 and an 056mag2. I think the modern saws are better. If I am wrong, let me know.



A Stihl MS 880 is listed at 8.6 HP

A Husqvarna 3120XP is listed at 8.4 HP

IMO 101b you can expect at least 10HP, and there is room for quite a bit more.

As far as power goes, it is not even close. The 101b will cut at an engine speed far above the 9500 rpm rev limiter on a 3120xp.


----------



## blsnelling (Dec 6, 2011)

ozflea said:


> McCulloch Racing Engine sticker
> 
> 
> 
> ...



I *NEED *one of those, lol


----------



## blsnelling (Dec 6, 2011)

leeha said:


> If you find a place to chrome Magnesium, Please let me know.
> As far as i know it can't be done. All the chrome on the Mac
> kart engines is over aluminum. If you notice the chrome flywheel
> housing is much heavier than a painted one off a saw as well as
> ...



Well, I just got schooled, lol. So much for those ideas. Thanks for the info.


----------



## Jacob J. (Dec 6, 2011)

I've talked to a couple motorcycle shops about chrome-plating Magnesium and I think it possible from what I've heard.

Typically what they do is either deposit a layer of copper electrolytically and then chrome on top of that or they use a chromate conversion finish 
which is then polished. There's a couple of websites that claim to chrome-plate Mag. 

Chrome Plating services on Plastic, FIberglasss, Magnesium, Metal,

Black Chrome Plating - Arlington Plating Company


----------



## leeha (Dec 6, 2011)

Jacob J. said:


> I've talked to a couple motorcycle shops about chrome-plating Magnesium and I think it possible from what I've heard.
> 
> Typically what they do is either deposit a layer of copper electrolytically and then chrome on top of that or they use a chromate conversion finish
> which is then polished. There's a couple of websites that claim to chrome-plate Mag.
> ...




Nice info Jacob, The couple chrome shops i have delt with
said they can't do it. 
I will check them out. Although i bet it's very pricey.


Lee


----------



## Jacob J. (Dec 6, 2011)

leeha said:


> Nice info Jacob, The couple chrome shops i have delt with
> said they can't do it.
> I will check them out. Although i bet it's very pricey.
> 
> ...



That's what I'm thinking. Although I can tell you, I'm highly tempted to go for that "Black Chrome"
on four or five of the big old saws I have, so if there's enough parts involved it may bring the price
down a bit. 
A local guy that does powder coating cuts me a pretty big break because I wait until I have a lot of
parts to do at once and I also sand blast them and scrub them down with fresh paint thinner before
I bring them in.


----------



## 54stude (Dec 6, 2011)

I you are looking for a bare "patina" look from magnesium that will not turn chalky and get the white death, I have heard this gibbs brand penetrant works well.

Gibbs Brand penetrant


----------



## Dennis Cahoon (Dec 6, 2011)

Lee, I saw a 2100 once that the owner polished the mag out and it looked just like crome. Lots of elbow grease, I would guess.


----------



## Dennis Cahoon (Dec 6, 2011)

Chopwood said:


> To those who actually have experiance: how do these karts compare to the modern big saws? I'm talking about 3120's and 88's. Dennis, what is your opinion? I have run a few 166's 2100's,SP125 and an 056mag2. I think the modern saws are better. If I am wrong, let me know.



I ported an 084 that I ran when I worked for Ericson helicopter that would smoke a 125 Mac. The 101's ran good but didn't last. In big wood getting 30 days without problems you were lucky. I didn't have 101's, but the 125's, I got rid of because they were a PITA to work on, and weren't that reliable for me. Most guys got away from them and the 2100 Homelites in the early 70's and went to 075 and 076's or 2100 Huskies. Except for a few diehards, the 125 faded away for smaller saws.


----------



## ozflea (Dec 6, 2011)

Polishing a saw's alloy looks great but man you gotta work at to keep the shine heres my old Solo Twin.











Mc Solo Bob


----------



## ozflea (Dec 6, 2011)

Dennis Cahoon said:


> I ported an 084 that I ran when I worked for Ericson helicopter that would smoke a 125 Mac. The 101's ran good but didn't last. In big wood getting 30 days without problems you were lucky. I didn't have 101's, but the 125's, I got rid of because they were a PITA to work on, and weren't that reliable for me. Most guys got away from them and the 2100 Homelites in the early 70's and went to 075 and 076's or 2100 Huskies. Except for a few diehards, the 125 faded away for smaller saws.



Your right Dennis the old 125's are a bit labour intensive against the new released saws but hey thats life even Mac moved into vertical cylinders making life a dam site easier and quicker 

101's where made to go not last a life time wear rates are high in kart engines.

McBob.


----------



## ozflea (Dec 7, 2011)

ozflea said:


> McCulloch Racing Engine sticker onm a 101 M/C see the decompressor Dennis
> 
> 
> 
> ...



Just in case you missed it Dennis see the decompressor


----------



## Dennis Cahoon (Dec 7, 2011)

Here's a little something that's a must, if you're gonna own a 125 or 101B.......Mac wrenchs.......try to find one of these NIB.....Hahahahahahaha!


----------



## 24d (Dec 7, 2011)

Dennis Cahoon said:


> Here's a little something that's a must, if you're gonna own a 125 or 101B.......Mac wrenchs.......try to find one of these NIB.....Hahahahahahaha!



Dennis! That picture of wrenches is my screen saver, I'v been drooling over them scents you put them up on the other site 4 or 5 years ago haha!

Brad, I'm having some camera issues but this is what my motor looks like, then the saw is all yellow. I plugged the decomp of course but it REALLY needs one, you have to really have your mind right to pull it.




I got it off an ultra lite airplane, I once read that this motor was the end of Mac, they built a bunch for some aircraft company then the deal fell though.

I have all new decals for the SP125s, I'll take some pictures and post them if anybody needs them or can duplicate them?
I could do a close up of the starter cover on that 101 also?


----------



## leeha (Dec 7, 2011)

I gots a few of thems screnchies too.
Brand new, never used.

Lee


----------



## watsonr (Dec 7, 2011)

Chopwood said:


> To those who actually have experiance: how do these karts compare to the modern big saws? I'm talking about 3120's and 88's. Dennis, what is your opinion? I have run a few 166's 2100's,SP125 and an 056mag2. I think the modern saws are better. If I am wrong, let me know.



Not really sure but I can say that my Homelite 750 probably would give an 066 more than just a run and it beats the 064 in big wood! It just may surprise you how strong they really are.



blsnelling said:


> I suspect it may be a shim used to set the endplay between crank bearings.
> 
> What are the two holes through the bore for the flywheel side crank seal?



I have never seen a shim used in there, just cover to cylinder with a sealant applied. The two holes are 10-24 machine screw holes and I use them to mount the puller when pulling the cover off. They do get plugged with the points cover or something like that, so no empty hole is left.


----------



## nmurph (Dec 7, 2011)

watsonr said:


> Not really sure but I can say that my Homelite 750 probably would give an 066 more than just a run and it beats the 064 in big wood! It just may surprise you how strong they really are.



I have seen my 125 hand it to my 394 in 30" oak. The chains were not the same, but both were fresh ground, and I swapped saws back and forth with my brother just to make sure it wasn't the operator. The beat-down was obvious enough that any variables would be covered.


----------



## watsonr (Dec 7, 2011)

nmurph said:


> I have seen my 125 hand it to my 394 in 30" oak. The chains were not the same, but both were fresh ground, and I swapped saws back and forth with my brother just to make sure it wasn't the operator. The beat-down was obvious enough that any variables would be covered.



Not surprised, these old saws were all about torque. The new saws are about speed and we all know....TORQUE wins races. They carry the speed and torque well at 9-10K under load and those 088/3120 carry about the same speed in the cut, not sure if they carry the torque to match, probably close...but I know I can lean on the 750 hard and not slow it down.


----------



## little possum (Dec 7, 2011)

You could have them dipped. Skulls would be sick! :msp_tongue:


----------



## 24d (Dec 7, 2011)

An SP125 is a statement, a piece of history and a piece of it's owner. It's no longer a race contender or work saw, it's just a big loud statement, make it say anything you want. I'v never seen an ugly one.


----------



## Jacob J. (Dec 7, 2011)

24d said:


> An SP125 is a statement, a piece of history and a piece of it's owner. It's no longer a race contender or work saw, it's just a big loud statement, make it say anything you want. I'v never seen an ugly one.



For a man to have gone out and made a living with these saws is something to really think about. I remember my old man staying up all night to rebuild a couple of 125s or P-62s and then leaving at 4 a.m. to go cut the big wood.


----------



## 24d (Dec 7, 2011)

Jacob J. said:


> For a man to have gone out and made a living with these saws is something to really think about. I remember my old man staying up all night to rebuild a couple of 125s or P-62s and then leaving at 4 a.m. to go cut the big wood.



For sure! A special event is one thing but making a living with one, my hat is off to anyone that did it.
Big saw 
SP125:chainsawguy:


----------



## nmurph (Dec 7, 2011)

24d said:


> An SP125 is a statement, a piece of history and a piece of it's owner. It's no longer a race contender or work saw, it's just a big loud statement, make it say anything you want. I'v never seen an ugly one.



I look for every reason to run mine. Got a 14" stump? Might as well drag the 125 to it!!! I have smaller and lighter saws that will do most things I encounter as well as the 125, but none of them make the same satifying noise as the Mac.


----------



## rwoods (Dec 7, 2011)

Dennis Cahoon said:


> Here's a little something that's a must, if you're gonna own a 125 or 101B.......Mac wrenchs.......try to find one of these NIB.....Hahahahahahaha!



They are still available on eBay: MCCULLOCH WRENCH SCRENCH TOOL 9/16" BAR NUT | eBay Nice wrench. I wish there was a ten series equivalent but all I can find are stamped. Ron


----------



## ausneil 1 (Dec 7, 2011)

Dennis Cahoon said:


> Here's a little something that's a must, if you're gonna own a 125 or 101B.......Mac wrenchs.......try to find one of these NIB.....Hahahahahahaha!




I have seen those years ago, thought they were just 9/16 ring spanner with the 1/2 in end cut off and flattened.
never knew they would be worth money today.

I have never fell with the 125, but i have asked many old fellers who did and they seem to have a soft spot for them but all went over to 090 stihls.
All agree the 090 was the saw to own.


----------



## ozflea (Dec 7, 2011)

Did we wake you or are you lookin' to git your mouth washed out Neil ............... 090's different horse for a different course 

McBob.


----------



## Eccentric (Dec 7, 2011)

rwoods said:


> They are still available on eBay: MCCULLOCH WRENCH SCRENCH TOOL 9/16" BAR NUT | eBay Nice wrench. I wish there was a ten series equivalent but all I can find are stamped. Ron



Make your own. I just bought a set of offset box end wrenches from HF on sale to do just that. Grab the 1/2" offset and cut the other end off. Grind that end into a flatblade screwdriver. If it's a 1/2" and 9/16" combo then you can cut it in the middle and make one for the big 'uns and another for the 10-series. 5/8" works for big Homelite bar nuts (and for the small spark plugs used on 10-series Macs). 3/4" works for most other saw spark plugs (and creamsickle bar nuts), and 13/16" works for the old J6J and J8J type plugs. You may have to grind a little meat from around the box end to clear the fins on the cylinder. I've seen 13mmX16mm (basically 1/2" by 5/8") screnches for sale too. That'd cover the bar nut and plug on a 10-series...


----------



## Anthony_Va. (Dec 7, 2011)

nmurph said:


> I have seen my 125 hand it to my 394 in 30" oak. The chains were not the same, but both were fresh ground, and I swapped saws back and forth with my brother just to make sure it wasn't the operator. The beat-down was obvious enough that any variables would be covered.



Can you imagine how bad the beating would be in 40"+ Oak with 50" bars? :msp_biggrin:

I'm starting to want one of these saws myself. I hope to be at a GTG when Brad pulls this beast out to run.


----------



## blsnelling (Dec 7, 2011)

blsnelling said:


> What are the two holes through the bore for the flywheel side crank seal?



Anyone? Looks like seal positioning is critical or a major air leak will result.


----------



## Jacob J. (Dec 7, 2011)

blsnelling said:


> Anyone? Looks like seal positioning is critical or a major air leak will result.



Are you talking about holes through the block where the seal seats? I haven't seen those on any of my 101 blocks.


----------



## ozflea (Dec 7, 2011)

Are you talking of the two screw holes for the point set anchoring 

I JUST ADD A BIT OF PERMASEAL to the threads of the screws as i don't run points and condensor make sure those two screws are very snug.

McBob


----------



## Brian13 (Dec 7, 2011)

blsnelling said:


> Anyone? Looks like seal positioning is critical or a major air leak will result.



Got a pic. Sounds like the weep hole, main seal goes under that hole, and thinner seal goes above it. If I am at all understanding what your talking about.


----------



## ausneil 1 (Dec 7, 2011)

ozflea said:


> Did we wake you or are you lookin' to git your mouth washed out Neil ............... 090's different horse for a different course
> 
> McBob.





hahah,I have a soft spot for them as well and i'm not knocking them in any way or form, merely stating what some of our old timers have said to me who did work in our big timber in the 60's and 70's.

Even old Bill Boyd ( hardened mac man and lifelong professional log faller) said they were a top saw but they spent a lot of time in the workshop and his 090's hardly ever missed a beat. He gave me his entire mac collection from his working days which amounted to a lot of preloved stuff. I gave him a carton of tooheys old stubbies and he was satisfied.


----------



## ozflea (Dec 7, 2011)

At least Bill will be happy 

McBob.


----------



## blsnelling (Dec 7, 2011)

blsnelling said:


> Anyone? Looks like seal positioning is critical or a major air leak will result.





Jacob J. said:


> Are you talking about holes through the block where the seal seats? I haven't seen those on any of my 101 blocks.





Brian13 said:


> Got a pic. Sounds like the weep hole, main seal goes under that hole, and thinner seal goes above it. If I am at all understanding what your talking about.



This cover may very well be from a SP125. 

















There isn't room for two of these seals.


----------



## Brian13 (Dec 7, 2011)

Yes that is the weep hole, iirc its to keep any oil out of the points. Should have one regular seal that sits just below that hole. And then one thin one that goes just above it.


----------



## blsnelling (Dec 7, 2011)

Brian13 said:


> Yes that is the weep hole, iirc its to keep any oil out of the points. Should have one regular seal that sits just below that hole. And then one thin one that goes just above it.



Why two seals? I've never seen a saw with double seals. Is it necessary with these new seals?


----------



## Brian13 (Dec 7, 2011)

blsnelling said:


> Why two seals? I've never seen a saw with double seals. Is it necessary with these new seals?



That is the only series I have come across that have 2 seals like that. I have always reused the outer seal, because the bearing store I go to doesnt have a match for it. If you can find one I would put one on, cant give you a yes or no as to if it is absolutely necessary. It was there when I took it apart so I put the same back LOL.


----------



## Dennis Cahoon (Dec 7, 2011)

Don't worry Brad.......those holes are there just to let the steam out......Hahahahahahaha!


----------



## rupedoggy (Dec 7, 2011)

The hole between the seals are to keep from forcing a seal out, under pressure. You need two seals.
The other hole is to allow fresh air to the points. For some reason, unknown to me, the points will not work when all the air is burned by the points. or at least won't work well.


----------



## ozflea (Dec 7, 2011)

Dennis Cahoon said:


> Don't worry Brad.......those holes are there just to let the steam out......Hahahahahahaha!



Well you'd know Dennis your full of hot air.

McBob.


----------



## blsnelling (Dec 7, 2011)

According to Terry, which I understand you can take to the bank, the outer seal is a dust seal needed to keep saw dust and engine oil out of the points. It's not needed on a kart. I'm assuming I can leave it out of this saw since it's running an Atom module, so no points.


----------



## watsonr (Dec 7, 2011)

There is a cover that goes over the points to keep out the saw dust. Guess it wouldn't really matter on a kart...your building a saw.


----------



## blsnelling (Dec 7, 2011)

But the first one's not running points, so shouldn't need the seal. I've asked Terry for clarification on that point.


----------



## watsonr (Dec 7, 2011)

U could probably skip that seal and the points cover...however that slot in the raised area around the points holds a felt wiper. It would have soaked up any oil and does touch the crank to wipe it clean, I would not skip that part.


----------



## ozflea (Dec 7, 2011)

Na still use both seals if you can get em 

McBob.


----------



## McC (Dec 7, 2011)

Brian13, thanks for embedding my youtube video of me running my saw, and my cousin Paul running his saw. Mine is a mc92 in a 250 frame, .020 over with no mods to the ports. Running a mac v4 intake and a tilly hr carb. Pauls is a mc93 in a 250, pretty sure it's a mac v4, but he runs a tilly hl. They are very close in power. I usually have it set rich, don't want to stick it. Set rich it will make 3 cuts in a 10x10 in about 6-7 sec. This year I leaned it some and it ran much better and time went down to 5.7. Lots of fun to cut with.


----------



## ozflea (Dec 7, 2011)

The 92 and 93 are good engines and i don't quite grasp why the 91b/1 gets going a bit harder i have one here and at 100cc and a bit of port work it kills a 125cc 

The 91b/1 is an outstanding engine 

McBob.


----------



## Teddy.Scout (Dec 8, 2011)

Jacob J. said:


> I've talked to a couple motorcycle shops about chrome-plating Magnesium and I think it possible from what I've heard.
> 
> Typically what they do is either deposit a layer of copper electrolytically and then chrome on top of that or they use a chromate conversion finish
> which is then polished. There's a couple of websites that claim to chrome-plate Mag.
> ...





leeha said:


> Nice info Jacob, The couple chrome shops i have delt with
> said they can't do it.
> I will check them out. Although i bet it's very pricey.
> 
> ...




With the labor, prep, and actual material used to accomplish this,
(same as plastic with a micro layer of chrome)
Might as well gold plate it.
It is EXPENSIVE!

Looked hard at this when looking into options for a 090case.


----------



## 24d (Dec 8, 2011)

My sp125/101
View attachment 210494

View attachment 210495


----------



## ozflea (Dec 8, 2011)

Lookin' good ol mate did you block off the origional decompressor valve ?

A saw with a flowing flag of stars and stripes over the fuel tank would look tuff.

McBob.


----------



## ozflea (Dec 8, 2011)

And when 123cc is still not enough you can always shoehorn in a US820 Copperhead at 134cc 







And if ones not enough try two i'm easy to get along with 






Or two 101's 







McBob.


----------



## Dennis Cahoon (Dec 8, 2011)

Where's that decompressor McBob?.........Hahahahahahaha!




[/QUOTE]


----------



## ozflea (Dec 8, 2011)

Dennis Cahoon said:


> Where's that decompressor McBob?.........Hahahahahahaha!


[/QUOTE]

You'd better ask 24D that one ...................

McBob.

Here's my 101D twin BDC14's @ 133cc


----------



## blsnelling (Dec 8, 2011)

ozflea said:


> A saw with a flowing flag of stars and stripes over the fuel tank would look tuff.



Hmmmmm. I like that idea. Do we have any resident expert air brush artists on here. I'm a HUGE fan of flags and eagles!


----------



## leeha (Dec 8, 2011)

McBob, Still waiting to see some video's
of them dual engine saws running.




Lee


----------



## 24d (Dec 8, 2011)

It was the same as this one when I got it,




except it had a hub for a prop on it, I plugged the decomp. It REALLY needs a decomp, I just aint put one on it yet.
I only have $380.00 in it, $180 for a fair looking blown SP125c and $200 for the 101.
Bob, I thought about fixing it up a little but I kinda like it like it is, I can haul it to the camp or where ever without a second thought.


----------



## ozflea (Dec 8, 2011)

Although not ran in the timber here's my twin 101's running for the first time easy to start one starts the other sound crisp.

McBob.





You should be able to see the two different fan housings although both are chromed one is on a 101aa and the other is a 101b

Here's my twin SP125c


----------



## blsnelling (Dec 8, 2011)

That is way cool


----------



## ozflea (Dec 8, 2011)

24d said:


> It was the same as this one when I got it,
> 
> 
> 
> ...



Their a ##### to start without a decompressor hope you have tough fingers mate they don't have to look fancy to be a great saw but i like a 
bit of shine to mine just a personal thing really and shine doesn't make them any faster just prettier on the eyes 

The 101d i have above with the twin BDC's was a mungrel it kept bumping the decompressor shut early with the piston just added another washer to 
the decompressor and bingo fixed it before it tore my hand off.

McBob.


----------



## heimannm (Dec 8, 2011)

Hey Larry - haven't seen you post in a while. I think I may have that Super series flywheel cover with the three holes for the starter if you are still looking.

Ron - the two hole for pulling the side cover are tapped 1/4-20, but it turns out they are not the ones Brad was talking about anyway.

Roger Bennet (bennetz? on e-bay) has some reasonable quality reproductions of the flying flag emblem for the starter covers if anyone is interested.

Mark


----------



## ozflea (Dec 8, 2011)

Just for the lovers of all things Mac.






Mac Bob


----------



## blsnelling (Dec 8, 2011)

Do you have that in higher resolution?


----------



## ozflea (Dec 8, 2011)

blsnelling said:


> Do you have that in higher resolution?



Best i have flogged it off ebay.

McBob


----------



## 24d (Dec 8, 2011)

heimannm said:


> Hey Larry - haven't seen you post in a while. I think I may have that Super series flywheel cover with the three holes for the starter if you are still looking.
> Mark



Mark, Yea life held me up for a while ha! Yes I do still need that cover, funny thing, Dennis, Bob and I were just chatting about that funny little saw the other day. I had forgot all about it till Dennis pulled out a picture of it.

If it will help anyone, I'll shoot the starter cover decal, the SP125 decal, the oil pump decal and the decomp decal, I'v got a fairly nice camera and you should be able to make copies.


----------



## little possum (Dec 8, 2011)

blsnelling said:


> Hmmmmm. I like that idea. Do we have any resident expert air brush artists on here. I'm a HUGE fan of flags and eagles!


Yea. One of the members has done a couple bikes and helmets. He posted in either Slamms 441 thread, loggin thread, or the one with Porsches flame saw.


----------



## Ductape (Dec 8, 2011)

ozflea said:


> Just for the lovers of all things Mac.
> 
> 
> 
> ...





That sign is killer !!!!!


----------



## little possum (Dec 8, 2011)

I saw a few Mac 101A and 101B American flag decals..


----------



## 24d (Dec 8, 2011)

adam345 said:


> Dennis, at what RPM make 22hp the 101b does?I read all the posts and have seen a comment that makes 22hp now my question is how many rpm?



[email protected]! We sure have missed you!


----------



## ozflea (Dec 8, 2011)

24d said:


> [email protected]! We sure have missed you!





Don't tell me you missed all of us that much and now you've found us do we get more of your emails to block ?

Adam 345 or whatever go build a dyno then build the 101 then tell us if the 22 hp is achievable and at what RPM then all will know savy.

McBob.


----------



## Eccentric (Dec 8, 2011)

*I can't believe that cockroach is back again...*

Is that RPM's achieving with the ignition pointless or with the breakers I don't think is possible with points don't you no?


----------



## leeha (Dec 8, 2011)

ozflea said:


> Don't tell me you missed all of us that much and now you've found us do we get more of your emails to block ?
> 
> Adam 345 or whatever go build a dyno then build the 101 then tell us if the 22 hp is achievable and at what RPM then all will know savy.
> 
> McBob.



He would still come back, I believe he
lacks attention. So he will always be a 
pain in the Arssssssssssssssssssss




Lee


----------



## 24d (Dec 9, 2011)

ozflea said:


> Their a ##### to start without a decompressor hope you have tough fingers mate


I really have to get my mind right to pull it, luckily, it almost always starts the first time but yea, it's a #####.


ozflea said:


> They don't have to look fancy to be a great saw but i like a bit of shine to mine just a personal thing really and shine doesn't make them any faster just prettier on the eyes
> McBob.



I have all the parts to make a really nice looking black and chrome SP125 hotsaw, just haven't done it yet, one day though!
This saw here really looks pretty good, all the decals are still on it ect, just looks like a work saw, it's far from the time to sand it down and paint it.
On the bars, rollers are just to easy to get not to put one on an SP125, it just doesn't look as good with anything else. No matter what stage of life the saw is in, put a roller nose bar on it, just my .02.


----------



## Ambull (Dec 11, 2011)

Today I put a GEM muffler on one of my Kart saws. It originally had the directional type muffler that had been modified for the 101B exhaust port. IT worked ok, but this muffler to me looks really nice. This style is not as common as the conventional GEM box muffler. It fits much easier, and the two piece design makes it easier to mount.

Here is the exhaust port. Piston looks nice and clean.







Here is the bottom piece mounted. The third hole did not line up correctly. I will have to slot it a little to get the third screw in.






And here is the top piece mounted.


----------



## Jacob J. (Dec 11, 2011)

Those two-piece GEM mufflers look really sharp. They're a part of that great 1960's styling.


----------



## leeha (Dec 11, 2011)

Very nice muffler, I like the outlet.
Down and back. She should sound good.



Lee


----------



## Dennis Cahoon (Dec 11, 2011)

Jacob J. said:


> Those two-piece GEM mufflers look really sharp. They're a part of that great 1960's styling.



Not on the 125's......They have the drug store logger look IMO......Hahahahahahaha!


----------



## rwoods (Dec 11, 2011)

Ambull said:


> Today I put a GEM muffler on one of my Kart saws. It originally had the directional type muffler that had been modified for the 101B exhaust port. IT worked ok, but this muffler to me looks really nice. This style is not as common as the conventional GEM box muffler. It fits much easier, and the two piece design makes it easier to mount.
> 
> 
> Here is the bottom piece mounted. The third hole did not line up correctly. I will have to slot it a little to get the third screw in.
> ...



Ambull, I thought that was a cool muffler as well. I passed on it as I already have two of the more boxier styles. 

Personally, I like the way the two piece mufflers don't extend back as far towards your hand as the one piece GEM.






I had concerns with my front discharge that I would burn the sawdust flap but after a tank and a half Saturday morning no damage. I can't say that for my chaps though:










BTW do you have any plans to secure those bolts? I just know one on mine is going to find it's way into the exhaust port. I go back and forth between safety wire and stainless steel cotter pins. I thought of a locking plate as well but I don't want to interfere with the exhaust flow. My 125C is so much stronger than before the GEM. I don't know if it is so much the GEM as it is the removal of the old spark screen - but the saw sounds great even through ear muffs.

Ron


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## cpr (Dec 11, 2011)

Those are now the coolest chaps ever.


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## rupedoggy (Dec 11, 2011)

You branded your chaps. How do you do that? The muffler is on the right side and you somehow put the muffler against the chaps. You can clearly read GEM on the chaps. Are you left handed? What part of the chaps were branded? How do you run a saw?


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## Ambull (Dec 11, 2011)

Dennis Cahoon said:


> Not on the 125's......They have the drug store logger look IMO......Hahahahahahaha!



Wow I don't even get that joke.....

Anyways, Ron, I like to use the 10-24 bolts with the locking patch on them. Never had one come loose. Check out this link, and click on the self locking screws:

McMaster-Carr

I have another saw with the larger Gem muffler on it, and the rear shroud needed to be trimmed. Plus it kind of stinks that the third hole has to be drilled right through the "E".


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## Ambull (Dec 11, 2011)

BTW Ron, you are the bigger man for posting those shots of your chaps. You obviously were doing something that was not normal, but aren't afraid to show everyone. I would have squashed that story in a hurry.


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## rwoods (Dec 11, 2011)

rupedoggy said:


> You branded your chaps. How do you do that? The muffler is on the right side and you somehow put the muffler against the chaps. You can clearly read GEM on the chaps. Are you left handed? What part of the chaps were branded? How do you run a saw?



This happened from bumping my leg as I carried the hot saw back to the truck. I'll learn now to carry it left handed or with the bar facing forward when carrying it right handed.



Ambull said:


> Wow I don't even get that joke.....
> 
> Anyways, Ron, I like to use the 10-24 bolts with the locking patch on them. Never had one come loose. Check out this link, and click on the self locking screws:
> 
> ...



I think he's trying to say that guys with kart mufflers are pretend loggers. Personally I don't pretend to be anything more than a firewood hack.

Thanks for the reference on the bolts. Ron


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## heimannm (Dec 11, 2011)

I've burned holes in two set of chaps, normally when the saw is turned on it's side making a horizontal cut as in felling, and using your hip to help push the saw along.

View attachment 210984


Mark


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## rwoods (Dec 11, 2011)

heimannm said:


> I've burned holes in two set of chaps, normally when the saw is turned on it's side making a horizontal cut as in felling, and using your hip to help push the saw along View attachment 210984
> 
> 
> Mark



Mark, that's another thing I like about the big old MACs - sometimes you need some additional leverage just to keep them fed. Ron


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## ozflea (Dec 11, 2011)

I stick to the origional muffler the box type just pull the spark arrestor and refit the deflector i file out the exit hole for a little more performance but thats it.

I have a few spare NOS ones here.

McBob.


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## Urbicide (Dec 11, 2011)

Well Ron, it was a good thing that you were wearing your chaps. You might otherwise be permanently wearing* GEM* in a location not too far from the Jewels. The time might have come one day when you would have had to explain why the brand said GEM and not GEMS. Then you would honestly have to say that you had an accident with a huge chain saw. 
:chainsawguy:


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## 7oaks (Dec 11, 2011)

Urbicide said:


> Well Ron, it was a good thing that you were wearing your chaps. You might otherwise be permanently wearing* GEM* in a location not too far from the Jewels. The time might have come one day when you would have had to explain why the brand said GEM and not GEMS. Then you would honestly have to say that you had an accident with a huge chain saw.
> :chainsawguy:


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## Ambull (Dec 13, 2011)

Ambull said:


> OK Brad, I put together a vid to show how I start a 101B Mac. This one is .050 over, 129cc, no decomp. It has fresh rings, and I notice the compression has been on the rise, as it is getting harder and harder to turn over. Not the best cut, as I realized the filter was dirty after I made the cut.
> 
> [video=youtube;imVCsFHAx-g]http://www.youtube.com/watch?v=imVCsFHAx-g&feature=youtube_gdata[/video]



Just bumping this vid. My bro Terry was looking for it......


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## blsnelling (Dec 13, 2011)

Trust me, I haven't forgotten about this thread or the saws. I worked on 5 other saws last weekend that needed to be finished and moved out of the way. Also, I've volunteered to rebuild a 090G that was donated and will be sold to benefit Stumpy. I'll be back working on these soon though.


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## parrisw (Dec 13, 2011)

blsnelling said:


> Trust me, I haven't forgotten about this thread or the saws. I worked on 5 other saws last weekend that needed to be finished and moved out of the way. Also, I've volunteered to rebuild a 090G that was donated and will be sold to benefit Stumpy. I'll be back working on these soon though.



No worries Brad, we know!! That's a good thing your doing.


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## blsnelling (Dec 13, 2011)

parrisw said:


> No worries Brad, we know!! That's a good thing your doing.



Thanks Will. 

I did finally get a response back today from Boyesen. 


*Thank you for e-mailing the reed pictures to us. We have made this size reed in the past, in a single stage design, of fiber glass and carbon fiber material. 

1) The price for a set (2 pcs) in fiber glass material is $27.95 USD plus a $20 set-up fee, total amount of $47.95 USD + shipping.

2) The price for a set (2 pcs) in carbon fiber material is $47.63 USD plus a $20 set-up fee, total amount of $67.63 USD + shipping.

Please also let us know the material and material thickness of your stock reed.

Please contact us if you have any additional questions, or if you would like to place an order.*


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## Jacob J. (Dec 13, 2011)

That sounds about right. The guys on the karting forum that did the group buy got a good price since they got the quantity over 100 sets.


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## mt.stalker (Dec 13, 2011)

Ambull , you are fairly close to my location . I saw an add on craigslist for chainsaw modding in NE PA . Do you have any knowledge of this/who or quality of work ?

Thanks, John


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## Dennis Cahoon (Dec 13, 2011)

blsnelling said:


> I did finally get a response back today from Boyesen.
> 
> 1) total amount of $47.95 USD + shipping.
> 
> 2) total amount of $67.63 USD + shipping.



Wow! pretty dam expensive! for a $15.00 set of reeds.......buy from the kart guys or build your own.


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## Ambull (Dec 14, 2011)

mt.stalker said:


> Ambull , you are fairly close to my location . I saw an add on craigslist for chainsaw modding in NE PA . Do you have any knowledge of this/who or quality of work ?
> 
> Thanks, John



No I do not know this guy. Sorry.


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## 24d (Dec 14, 2011)

Dennis Cahoon said:


> Wow! pretty dam expensive! for a $15.00 set of reeds.......buy from the kart guys or build your own.


Cutting out reeds is the same as cutting thick paper, find the material you want and snip them right out.


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## Eccentric (Dec 14, 2011)

24d said:


> Cutting out reeds is the same as cutting thick paper, find the material you want and snip them right out.



Where do you get the material? I've got some old Macs and Homelites that have steel reeds which I'd like to replace with some fresh reeds made from 'modern' material.


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## cpr (Dec 14, 2011)

Eccentric said:


> Where do you get the material? I've got some old Macs and Homelites that have steel reeds which I'd like to replace with some fresh reeds made from 'modern' material.



G - 10 Fiberglass Sheet


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## leeha (Dec 14, 2011)

How thick would you make the average fiberglass reed.



Lee


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## cpr (Dec 14, 2011)

Good question. Never miced any of the ones I have.


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## OREGONLOGGER (Dec 14, 2011)

Eccentric said:


> Where do you get the material? I've got some old Macs and Homelites that have steel reeds which I'd like to replace with some fresh reeds made from 'modern' material.



Happy Holidays E...I use the same grade as the stock reeds from my Homelites and yellows. I get mine at the local hobby shop in sheets just a couple bucks a sheet and can't tell the difference when done cutting and works just like stock reeds. Take one off the Homelite and match the thickness pretty thin stuff when you go to the hobby shop you'll see the sheet you'll need...-T


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## Eccentric (Dec 14, 2011)

OREGONLOGGER said:


> Happy Holidays E...I use the same grade as the stock reeds from my Homelites and yellows. I get mine at the local hobby shop in sheets just a couple bucks a sheet and can't tell the difference when done cutting and works just like stock reeds. Take one off the Homelite and match the thickness pretty thin stuff when you go to the hobby shop you'll see the sheet you'll need...-T



Thanks T. Have you pulled any of your home made reeds (made from this material) after extended running to see if they show any signs of fatigue or fraying?


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## heimannm (Dec 14, 2011)

Don't worry Aaron, you'll know when they start to fray...

Mark


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## Ambull (Dec 14, 2011)

Supposedly the Boyson reeds are "two stage" I think, which gives a better response at idle and better top end. Have no idea how much difference it makes, but I have been told that it makes a huge difference. I am guessing that there are two thicknesses involved....... I wonder if they sell "uncut" versions of those reeds that you can cut yourself....? Or is it just two thin reeds that are partially overlapped?


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## Dennis Cahoon (Dec 14, 2011)

Vintage McCULLOCH 68074 Pair Reed Valve Mc-101 Go kart | eBay

Here's NOS for $24.......but I'd try V-Force Tassinarri to make you a complete carbon fiber reed system........if you want the best!


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## turtle561 (Dec 14, 2011)

here ya go-
'"PLUS Optimization uses multi-staged reed petals to distribute the engine’s pulse forces over more surface area. By using a multiple reed petal stack, it is possible to acheive peak horsepower AND durability. The patented multi-stage design incorporates a specially shaped top reed petal and a ported bottom reed petal. The top petal is lightweight and resilient for crisp throttle response at partial throttle or low RPMs. The stiffer, bottom petal is ported to provide maximum flow and horsepower at higher RPMs."


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## ozflea (Dec 14, 2011)

I'm sure what most of you are missing is the total reed area thats why the V4 reed gives the 101 and the SP125 such a lift in performance and why i chose to modifiy the airbox to let one use the sloper manifold and V4 reed block and keep stock appearance .




















And heres what a stock bog 125c goes like with this conversion.

Heres a good read on reshaping the reed stoppers for increased performasnce .................
http://macbobaust.com/steve3.html

McBob.


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## 24d (Dec 15, 2011)

Dennis Cahoon said:


> I'd try V-Force Tassinarri to make you a complete carbon fiber reed system........if you want the best!



That would be AWESOME! I'm going to look into that!

Chainsaws don't need a two stage reed. I switched from two stage to V-force in my ATV and I can tell more in the low end than the top, both were vastly improved. At some point in the process the carbon fiber is a sheet, just check around and find a sheet big enough to do the job. V-force, these guys Carbon Tech- Reeds That Win Championships or here http://www.treatland.tv/SearchResults.asp?Search=reed+sheet, I'm sure somebody will sell a little piece of carbon fiber and it can't cost but so much.


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## ozflea (Dec 15, 2011)

Did you read this link 

McCullock Kart's and comments from Steve O'Hara, ,,,,,,,

McBob.


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## blsnelling (Dec 15, 2011)

The Go Power reed cage I just bought has no stops at all. The manifold basically acts as a stop as close as the cage fits in there.


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## ozflea (Dec 15, 2011)

blsnelling said:


> The Go Power reed cage I just bought has no stops at all. The manifold basically acts as a stop as close as the cage fits in there.



Whats the reeds made of are they metal ? if so a broken reed is disarster fibre ones will do less damage if they fail.

McBob


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## Eccentric (Dec 15, 2011)

heimannm said:


> Don't worry Aaron, you'll know when they start to fray...
> 
> Mark



Well yeah Mark. I was trying to get a gauge of how long these 'homebrew' reeds cut from hobby shop fiberglass or CF would go before that happened.......



Ambull said:


> Supposedly the Boyson reeds are "two stage" I think, which gives a better response at idle and better top end. Have no idea how much difference it makes, but I have been told that it makes a huge difference. I am guessing that there are two thicknesses involved....... I wonder if they sell "uncut" versions of those reeds that you can cut yourself....? Or is it just two thin reeds that are partially overlapped?



The 2-stage reeds have stiffer bottom reeds with windows cut in them, and more flexible top reeds that cover said windows. Look at Turtle's RC2 reed system pics. The top reeds open at lower flow rates (and the intake charge flows through the ports in the bottom reeds........supposedly increasing charge velocity), while the stiffer bottom reeds only open up at higher flow rates for more flow. I used to run the fiberglass Boysens on my dirt bikes in the 1980's. They did seem to add more "snap" to the bottom end. Top end seemed about the same. Maybe a scosh stronger. The big thing was the piece of mind gained by ditching the SS reeds for ones that the engine could 'eat' with less damage....


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## blsnelling (Dec 15, 2011)

ozflea said:


> Whats the reeds made of are they metal ? if so a broken reed is disarster fibre ones will do less damage if they fail.
> 
> McBob



They're fiber reeds.


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## 24d (Dec 19, 2011)

Who saw is this?
View attachment 212208


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## cpr (Dec 19, 2011)

Looks like the one apse sold a couple years ago. I have a bunch of pictures of it. Beautiful saw.


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## 24d (Dec 19, 2011)

cpr said:


> Beautiful saw.



Yes, it sure is that.


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## 54stude (Dec 19, 2011)

ozflea said:


> I'm sure what most of you are missing is the total reed area thats why the V4 reed gives the 101 and the SP125 such a lift in performance and why i chose to modifiy the airbox to let one use the sloper manifold and V4 reed block and keep stock appearance .
> 
> And heres what a stock bog 125c goes like with this conversion.
> 
> McBob.



For argument sake, how close to a true "kart saw" would a 123cc mac stock saw (797, sp125, cp125) be with a v4 reed setup, sloper intake, and big carb?

For example, unported 101b saw = 100%
then unported sp125 v4 sloper saw = ??%
and stock sp125 = ??%

I understand 797 and cp125 porting might be a little better than some other saws, but how much of the "kart saw" is in the kart block and porting, and how much is carburation, intake, and reeds?

Thanks in advance to all of the knowledgeable guys on here for sharing info!


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## cpr (Dec 19, 2011)

Far from an expert and I'm not sure it is totally quantifiable, but I'd say it has to work as a system. 1:1 changes, the intake is worth more than porting, but to maximize either, you need both since that's how they were designed to run. Bob's SP-125 block with sloper and big carb works so well because he's ported it to maximize the whole shootin' match.


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## ozflea (Dec 20, 2011)

54stude said:


> For argument sake, how close to a true "kart saw" would a 123cc mac stock saw (797, sp125, cp125) be with a v4 reed setup, sloper intake, and big carb?
> 
> For example, unported 101b saw = 100%
> then unported sp125 v4 sloper saw = ??%
> ...



Well the major difference is the removable head on the 101 and boost ports the 125 has neither unless your like me and do the boost port mod on the 125 ports are standard and the same in both cases.

The saw in the video has not had the ports altered it is stock.

McBob.


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## blsnelling (Dec 27, 2011)

I had some time this afternoon to make some good progress on this 1st 101 engine.

New bearings installed on the crank.






Crank installed and PTO side seal installed.





The first of the two flywheel side seals.





Second seal.


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## blsnelling (Dec 27, 2011)

Goo grease to hold the new rod bearing needles.















New 190,000 rod bolts.





Torqued to 90 in pounds.





This one his the block a little.





Beveled just a little for clearance.


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## blsnelling (Dec 27, 2011)

Block sanded smooth and flat on the sealing surface.















The oil tank will be coming back off. I need a gasket for it. I wanted to get the engine closed up.


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## RTK (Dec 27, 2011)

Looking Good


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## Tzed250 (Dec 27, 2011)

That interference between the rod bolt and case is one of the reasons for the use of the spline drive bolts.

BTW, what bearings and seals did you use? I need a set!


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## blsnelling (Dec 27, 2011)

Tzed250 said:


> That interference between the rod bolt and case is one of the reasons for the use of the spline drive bolts.
> 
> BTW, what bearings and seals did you use? I need a set!



Both were provided by Terry Ives. I can get you PNs for the seals if you'd like.


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## leeha (Dec 27, 2011)

Tzed250 said:


> That interference between the rod bolt and case is one of the reasons for the use of the spline drive bolts.
> 
> BTW, what bearings and seals did you use? I need a set!




The factory allen head rod bolts have a rounded head so
they clear the block.

Brad, Did these rod bolts come from Terry as well?
They look like standard hardware.


Lee


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## blsnelling (Dec 27, 2011)

leeha said:


> Brad, Did these rod bolts come from Terry as well?
> They look like standard hardware.
> 
> 
> Lee



Yes. They are 190,000 psi bolts.


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## leeha (Dec 27, 2011)

Good to know. I will be placing an order with Terry soon.
Waiting for pistons to arrive.




Lee


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## Tzed250 (Dec 27, 2011)

blsnelling said:


> Both were provided by Terry Ives. I can get you PNs for the seals if you'd like.



That would be great!


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## blsnelling (Dec 27, 2011)

The seals are SKF 6763 and 6816, available from NAPA.


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## Tzed250 (Dec 27, 2011)

Is it two of the 6763 and one of the 6816?


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## blsnelling (Dec 27, 2011)

Tzed250 said:


> Is it two of the 6763 and one of the 6816?



No. You cannot use two of these seals on the flywheel side. They are too thick. I used the original outer seal. The outer seal isn't used on a cart engine, and this saw will not have points. I could have actually left it out. The purpose for the outer seal was discussed some pages back.


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## Tzed250 (Dec 27, 2011)

blsnelling said:


> No. You cannot use two of these seals on the flywheel side. They are too thick. I used the original outer seal. The outer seal isn't used on a cart engine, and this saw will not have points. I could have actually left it out. The purpose for the outer seal was discussed some pages back.



I gotcha. The NOS points box I have has a new seal in it anyway. Thanks!!!


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## MechanicMatt (Dec 27, 2011)

Hey Brad, If I were you Id throw that rod bolt on a scale weigh it then grind the other bolt to match the weight. Im not sure what you other fellas think about it but I would like to learn. When building small blocks for my buddies we start with the lightest rod then shave the rest down to its weight. Just helps them hold together. Does it matter on such a small engine? The only thing is in the back of my mind I know what kinda off speed Id be trying to get out of that engine. Ill stop babbling now.


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## Anthony_Va. (Dec 27, 2011)

MechanicMatt said:


> Hey Brad, If I were you Id throw that rod bolt on a scale weigh it then grind the other bolt to match the weight. Im not sure what you other fellas think about it but I would like to learn. When building small blocks for my buddies we start with the lightest rod then shave the rest down to its weight. Just helps them hold together. Does it matter on such a small engine? The only thing is in the back of my mind I know what kinda off speed Id be trying to get out of that engine. Ill stop babbling now.



I don't think there's any way to really balance a chainsaw engine. I may be wrong though.


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## blsnelling (Dec 27, 2011)

Correct. That's not an issue on these single cylinder chainsaw engines. We sometimes remove a fair amount of material from the piston when doing a port job.


----------



## Jacob J. (Dec 27, 2011)

Anthony_Va. said:


> I don't think there's any way to really balance a chainsaw engine. I may be wrong though.



Right. You don't balance a single-cylinder engine unless you're balancing it on your chin.


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## MechanicMatt (Dec 27, 2011)

Hmm, I didn't think of that guys. I forgot you boys sometimes remove the skirt. But the skirt isn't spinning it's only going up and down. Just a thought fellas. I get what your talking about JJ there is nothing in there to balance it. No 2nd rod. Hey Brad you gonna have it running by this weekend? Seems your back on track.


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## Tzed250 (Dec 27, 2011)

IIRC most singles are balanced at 60% of the recip. mass. Another no free lunch deal. Everything you do to counteract the motion of the piston ends up shaking 90° from that axis.


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## blsnelling (Dec 27, 2011)

MechanicMatt said:


> Hey Brad you gonna have it running by this weekend? Seems your back on track.



I doubt it. None of the other parts have been cleaned or painted yet. Also, starting Thursday, I'll be tiling my master bathroom.


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## Tzed250 (Dec 27, 2011)

Here is a single with perfect primary balance. Ducati Supermono engine. Notice the second rod 90° from the main rod and piston. The balance rod is toggled to a rocker which dummies a second piston. This engine revved to over 10,000 RPM which is quite high for a 500cc single. The engine had a slight secondary imbalance. A rocking couple induced because the rods sat side-by-side on a common crankpin.


----------



## Jacob J. (Dec 27, 2011)

Tzed250 said:


> Here is a single with perfect primary balance. Ducati Supermono engine. Notice the second rod 90° from the main rod and piston. The balance rod is toggled to a rocker which dummies a second piston. This engine revved to over 10,000 RPM which is quite high for a 500cc single. The engine had a slight secondary imbalance. A rocking couple induced because the rods sat side-by-side on a common crankpin.



That is freakin' cool. I actually had a saw vibrate a lot once after I put a piston in it that was _too_ light. It was around 60% of the weight of the stock piston.
So I went back in and lightened the flywheel and crank and got it back to where it needed to be. It did lose some torque after that, but the acceleration and 
chain speed was ferocious.


----------



## buzz sawyer (Dec 27, 2011)

blsnelling said:


> No. You cannot use two of these seals on the flywheel side. They are too thick. I used the original outer seal. The outer seal isn't used on a cart engine, and this saw will not have points. I could have actually left it out. The purpose for the outer seal was discussed some pages back.



Brad, it's looking like another winner but I wanted to comment on the seals on the flywheel side. The old Homelite EZ, EZ6, 5-20, etc. used two seals per side - one with the lip pointing in an one pointing out. Since these are single lip seals, I had always assumed this was to seal against the vac and pressure pulses as the saw is running. On the flywheel side of my SP125Cs, the parts manual shows the same seal config. The inner seal goes in with the flat side out/lip in but the outer seal goes in with the flat side in/lip out so the single lips are facing in opposite directions. Again, I assumed that it was to seal against the + and - pressure pulses. The crank seal is much heavier and has a double lip. You picture shows both of the flywheel seals with the flat side out - I don't know how the seal lip corresponds to the face of the seal. 

Maybe I totally misunderstand the design, just wanted to throw out a little caution base on my experience. 
Anyone - feel free to correct me.


----------



## leeha (Dec 27, 2011)

Not really correct Buzz. On the Mac's i have rebuilt and thats many.
Both seals go in the same way. There is a hole drilled in the case
that goe's in between the two seals. The idea as i understand is if
the inner sealed had any weepage the second seal would prevent
the weepage from getting into the points but let it exit out the hole
into a felt block that is held in place by one of the points cover lock tabs.




Lee


----------



## Tzed250 (Dec 28, 2011)

leeha said:


> Not really correct Buzz. On the Mac's i have rebuilt and thats many.
> Both seals go in the same way. There is a hole drilled in the case
> that goe's in between the two seals. The idea as i understand is if
> the inner sealed had any weepage the second seal would prevent
> ...



So are there three different seal part numbers?


----------



## blsnelling (Dec 28, 2011)

Tzed250 said:


> So are there three different seal part numbers?



Correct.


----------



## blsnelling (Dec 28, 2011)

This is straight from Terry Ives.
_
"The magneto side McCulloch engines ran a pressure seal next to the crank case, they also ran a dust seal next to the ignition side. That was to keep saw dust and engine oil out of the ignition. Since we use the engines for karting, you do not need to run the dust, oil seal."_


----------



## husq2100 (Dec 28, 2011)

would the balance the saw to a specific rpm area, ie where it would be at cutting speed in wood???


----------



## buzz sawyer (Dec 28, 2011)

leeha said:


> Not really correct Buzz. On the Mac's i have rebuilt and thats many.
> Both seals go in the same way. There is a hole drilled in the case
> that goe's in between the two seals. The idea as i understand is if
> the inner sealed had any weepage the second seal would prevent
> ...



Thanks for clearing that up - makes sense and I wondered how it would seal against pressure with the hole. 
Here's the drawing I referred to from my manual. This is how both saws were when I tore them down. This is looking at the inside of the crankcase cover. Looks like the flat sides face each other - or maybe just a bad drawing that was revised in a later version? Since the outer seal doesn't seal against pressure, does it really make a difference which side goes in or out?


----------



## adam345 (Dec 28, 2011)

the centrifugal force produced by the inertia of the flywheel is strong enough it would be best lighten the wheel and cut a piece of lighten flywheel fins would have less weight which can go faster and with less inner strength she explained centrifuged my father from certain rpm it produces many internal forces in the motor and just destroying everything.


----------



## Tzed250 (Dec 28, 2011)

Here we go...


----------



## boda65 (Dec 28, 2011)

adam345 said:


> the centrifugal force produced by the inertia of the flywheel is strong enough it would be best lighten the wheel and cut a piece of lighten flywheel fins would have less weight which can go faster and with less inner strength she explained centrifuged my father from certain rpm it produces many internal forces in the motor and just destroying everything.



That sense not make my mother says my saws cold in garage not run at all.


----------



## ausneil 1 (Dec 28, 2011)

adam345 said:


> the centrifugal force produced by the inertia of the flywheel is strong enough it would be best lighten the wheel and cut a piece of lighten flywheel fins would have less weight which can go faster and with less inner strength she explained centrifuged my father from certain rpm it produces many internal forces in the motor and just destroying everything.





:msp_confused: ?????????????


----------



## adam345 (Dec 28, 2011)

Originally Posted by adam345 
the centrifugal force produced by the inertia of the flywheel is strong enough it would be best lighten the wheel and cut a piece of lighten flywheel fins would have less weight which can go faster and with less inner strength she explained centrifuged my father from certain rpm it produces many internal forces in the motor and just destroying everything.
Originally Posted by Tzed250 
Here is a single with perfect primary balance. Ducati Supermono engine. Notice the second rod 90° from the main rod and piston. The balance rod is toggled to a rocker which dummies a second piston. This engine revved to over 10,000 RPM which is quite high for a 500cc single. The engine had a slight secondary imbalance. A rocking couple induced because the rods sat side-by-side on a common crankpin.


----------



## Tzed250 (Dec 28, 2011)

Lord love a duck....have I actually been drug into this????


----------



## ozflea (Dec 28, 2011)

Lets just stay on track forget the rabbiting on and get the engine going those bolts for the rod are the wrong ones you need the splined bolts sorry unless you want a rattler instead of an engine 
Torque for the splined bolts is 110 in pds as far as the seals go as per the pic their back to back.

McBob.


----------



## ausneil 1 (Dec 28, 2011)

ozflea said:


> Lets just stay on track forget the rabbiting on and get the engine going those bolts for the rod are the wrong ones you need the splined bolts sorry unless you want a rattler instead of an engine
> Torque for the splined bolts is 110 in pds as far as the seals go as per the pic their back to back.
> 
> McBob.





Well said. :msp_thumbup:


----------



## leeha (Dec 28, 2011)

ozflea said:


> Lets just stay on track forget the rabbiting on and get the engine going those bolts for the rod are the wrong ones you need the splined bolts sorry unless you want a rattler instead of an engine
> Torque for the splined bolts is 110 in pds as far as the seals go as per the pic their back to back.
> 
> McBob.



Mr. McBob, I have to disagree on the seals. I have had many, and i mean many
big inch Mac's appart, Weather it be an 890, 895, 740, 790, 795, 797, or SP125,
I have never seen the flywheel side seals back to back. Not even once. I have had
a few that had never been appart.



Lee


----------



## ozflea (Dec 28, 2011)

Sorry Lee but what Mac says is right in my books what you do is your doing not mine, sorry to disagree.

McBob.


----------



## rwoods (Dec 28, 2011)

All my IPL's (karts and 125s) show the seals back to back. My one and only dismantled 101B has them both with lips inward. If it weren't for the weep hole I would had bet the MAC draftsman just made a mistake - but with the weep hole the outer seal really should have no pressure or vacuum to deal with so I don't see why it would make any difference how the outer seal is placed - but since I don't know I am going to follow the IPL and replace mine back to back. Ron


----------



## CM76 (Dec 28, 2011)

I have had a decent number of 125's apart as well, and have found all my seals installed with the lips inward (toward the crankcase) as Lee stated. Here are some disassembly photo's of one of my SP125's which appeared to have been unmolested from factory.

Regards,

Chris.


----------



## Jacob J. (Dec 28, 2011)

I've been through about 17 of the 125 motors and every seal was installed the way Lee is referring to. 
Pes+ told me about a cool trick though, installing the inner flywheel side seal with the lip facing outward. 
He said the seal would last longer that way. I haven't tried it yet but have been tempted to. 

Several of the saws I've taken apart were converted to solid state ignitions and did not have
the second "dust cover" seal and they ran fine without it.


----------



## ozflea (Dec 29, 2011)

Since we all have different ideas and since the saws have been around a very long time do, as you see fit .... me i'll stick to what i was taught by McCulloch unless you's know better.

McBob.


----------



## blsnelling (Dec 29, 2011)

ozflea said:


> those bolts for the rod are the wrong ones you need the splined bolts sorry unless you want a rattler instead of an engine



So are you saying Terry Ives sold me the wrong bolts? AFAIK, he's the best Mac builder out there.


----------



## ozflea (Dec 29, 2011)

blsnelling said:


> So are you saying Terry Ives sold me the wrong bolts? AFAIK, he's the best Mac builder out there.



There's a few good Mac builders around and Terry is one of them Mac used splined head bolts and with them cured the clearance problems 
you encounted in all the years i ran Mac's i think i had one failure put down to bolts but that was my fault for over revving the engine.

This brings to light the weakness in the 125's no compression control the 101 you can up the compression to slow the piston but in a 125
you can't so you must watch the revs and limit them.

McBob.


----------



## Jacob J. (Dec 29, 2011)

blsnelling said:


> So are you saying Terry Ives sold me the wrong bolts? AFAIK, he's the best Mac builder out there.



Brad- it's pretty safe to say that you can take Terry's advice to the bank. He's built more championship kart engines than every single person on this forum combined. If Terry says it's good, then in Terry I trust.


----------



## ozflea (Dec 29, 2011)

Jacob J. said:


> Brad- it's pretty safe to say that you can take Terry's advice to the bank. He's built more championship kart engines than every single person on this forum combined. If Terry says it's good, then in Terry I trust.



I agree Terry's advice is fine and you can use those bolts the reason that they are stronger in yield strength than the Mac bolts but expensive compared 
to the Mac splined bolts .......... you can use what you want but i'll stick with the Mac splined stuff and they dont have to be modded.

Some use the bolts Dave Bonbright suggest's from the US820 stronger again i have them here for my US820 Copperhead not needed really unless 
you push the engine of any mac over the top.
Some of those bolts need modding with they are seated area too before use or will cause the cap to fail.

McBob.


----------



## ozflea (Jan 3, 2012)

Here's the thin seals for the 101, 125 and PM 105, 125, There fitted back to back 

The O'ring between the side plate and the crankcase replaces the gasket make sure you use a snug fitting O'ring.

McBob.


----------



## cpr (Jan 3, 2012)

Funny about that side cover gasket. It's a dead-nuts fit as a head gasket.


----------



## leeha (Jan 3, 2012)

ozflea said:


> Here's the thin seals for the 101, 125 and PM 105, 125, There fitted back to back
> 
> The O'ring between the side plate and the crankcase replaces the gasket make sure you use a snug fitting O'ring.
> 
> McBob.




You can't use an "O" ring where the #62 gasket is on any 123cc Mac
do to the cut out in the block. All of the 123cc Mac's i have had appart 
were sealed with some type of sealing compound. You can use a gasket
but i haven't seen a gasket yet in all the 123cc Mac's yet. Funny how the
101 IPL shows a gasket but the 797, CP125, SP125 show nothing.
I will continue to install the seals the way i have always seen them.


Lee


----------



## RiverRat2 (Jan 3, 2012)

Wow,,, I stay away from this tred a few days and miss all of this!!!opcorn:opcorn:opcorn:


----------



## heimannm (Jan 3, 2012)

I pulled apart a 795 based cut off saw (Target Quik Cut) last night and found the two seals under the points on that model as well. They were both installed with the lips pointing out in case anyone is interested.

Mark


----------



## Jacob J. (Jan 3, 2012)

cpr said:


> Funny about that side cover gasket. It's a dead-nuts fit as a head gasket.



There's a reason for that...



leeha said:


> You can't use an "O" ring where the #62 gasket is on any 123cc Mac
> do to the cut out in the block. All of the 123cc Mac's i have had appart
> were sealed with some type of sealing compound. You can use a gasket
> but i haven't seen a gasket yet in all the 123cc Mac's yet. Funny how the
> ...



I've been using the old-school grey Dirko sealer. No O-rings or gaskets.

The O-rings work on the early kart engines with the flat mating surface.


----------



## ozflea (Jan 3, 2012)

I have always used O'rings to seal this joint have bags of them no sealer needed.

McBob.


----------



## leeha (Jan 3, 2012)

ozflea said:


> I have always used O'rings to seal this joint have bags of them no sealer needed.
> 
> McBob.



How is the "O" ring going to seal where the 
cut out is for the crank install. It won't.




Lee


----------



## ozflea (Jan 3, 2012)

leeha said:


> How is the "O" ring going to seal where the
> cut out is for the crank install. It won't.
> 
> 
> ...



Well you do your thing and i'll do mine Okkie Dokie

McBob.


----------



## leeha (Jan 4, 2012)

ozflea said:


> Well you do your thing and i'll do mine Okkie Dokie
> 
> McBob.



Just tell me how's an "O" ring going to
seal with the cut out in the block.
I'm listening. Mac doesn't use them in
any 123cc motor.


Lee


----------



## ozflea (Jan 4, 2012)

Well my engines run fine and no air leaks ...........................

McBob.


----------



## leeha (Jan 4, 2012)

Looks like the Mcculloch Master can't answer my question.




Lee


----------



## blsnelling (Jan 4, 2012)

leeha said:


> Just tell me how's an "O" ring going to
> seal with the cut out in the block.
> I'm listening. Mac doesn't use them in
> any 123cc motor.
> ...



You're referring to the cut out to clear the rod journal off the crank, correct? No way an o-ring would do anything to seal the side cover.


----------



## leeha (Jan 4, 2012)

blsnelling said:


> You're referring to the cut out to clear the rod journal off the crank, correct? No way an o-ring would do anything to seal the side cover.



That is correct Brad, Thats why all of the
123cc Mcculloch IPL's show no "O" ring.
Mcculloch used some sort of sealing stuff
to seal the case. Which also sealed the 3
open screw holes to prevent any leakage.
The 101 IPL is the only one to show a gasket.
But all the 101's i have had appart have had 
sealer and no gasket.



Lee


----------



## Jacob J. (Jan 4, 2012)

Every 125 I've pulled apart had some kind of sealer. All of my dad's saws were sealed back in the '70's when he rebuilt them
with the old-school Yamabond (in addition to being a McCulloch nut, he was a Yamaha guy.) I believe in those days the 
Yamabond was light blue. No gaskets or O-rings. On the saws that he had switched to the solid-state ignition, he'd only 
installed one seal per side. These were saws he ran for years in big timber with long bars and they did fine that way. 

He still had three saws though with points- two 797s and a CP-125. Those all had the original configuration as far as 
seals go.


----------



## ozflea (Jan 4, 2012)

Well debating to use an O'ring or not is not my arguement here, it's what i use .... you do what you want its your choice.
and it works for me regardless of what you think.

After seeing great blobs of silastic and god know what else used to seal this joint and seeing the excess dribbling everywhere inside the engine i'll stay with the o"ring.

McBob.


----------



## ozflea (Jan 10, 2012)

Well it's a tad quite here that bloody Mac will be a rusty mess if you dont get ya finger out.

McBob.


----------



## cpr (Jan 10, 2012)

Bob, when you mounted the carb did you use a spacer or cut the shroud and grind the fins to get it on?


----------



## ozflea (Jan 10, 2012)

I cut the airbox flloor out you need to take a lot out right back to the rear edge of the airfilter lip it's a very snug fit use the 92, 93/101 MC sloper manifold and you'll need to make a new throttle rod.
You can only run the auto oiler as the manual pushrod gets left out sorry.

If you do this mod on a SP125 no sweat use the standard rear mount 
If you using a 101 then you will have to ue a steel cylinder housing off a 101 and drill and mount a SP125 rear mount to it.
The cylinder wether its a 101 or 125 is not modified for the airbox hotup 











Now you cannot fit a alky carb because there simply not the room.


McBob.


----------



## cpr (Jan 11, 2012)




----------



## blsnelling (Jan 11, 2012)

I'm not at home and need to know what size the reed plate bolts are. 12-24 or 10-24?


----------



## ozflea (Jan 11, 2012)

cpr said:


>



Thats fine and the right setup now gut the floor out of the airbox it's a snug fit width wise just be careful you don't file the sides and hole the fuel tank 
You may need to use manifold gaskets and file the rear fin i didn't on mine it fitted just fine.

McBob.


----------



## ozflea (Jan 11, 2012)

blsnelling said:


> I'm not at home and need to know what size the reed plate bolts are. 12-24 or 10-24?



1/4" unf


----------



## blsnelling (Jan 11, 2012)

ozflea said:


> 1/4" unf



These aren't near that large.


----------



## RTK (Jan 11, 2012)

cpr said:


>





Can't rotate 180??


----------



## Dennis Cahoon (Jan 11, 2012)

Just make an aluminum plate in the shape of your reed gasket for a little rise. You might have to replace your studs for more lenght.


----------



## cpr (Jan 11, 2012)

Must
Cause
Confusion
Using
Lots &
Lots
Of
Crazy
Hardware
:bang:

EDIT: I figured it out. Like all good sarcasm, there's some truth at work here. Continues over on my build. Sorry for the hi-jack Brad.


----------



## ozflea (Jan 12, 2012)

Dennis Cahoon said:


> Just make an aluminum plate in the shape of your reed gasket for a little rise. You might have to replace your studs for more lenght.



Still wont make a difference using a spacer plate cause the fuel tank wont fit properly.

Just see if you can angle the lower edge of the pump section of the carb i didn't have any problems doing mine and i have done a couple.

McBob


----------



## Dennis Cahoon (Jan 12, 2012)

No matter how yours fits McBoob it's a hack job at best. I think he's trying to make his look nice and have everything work.


----------



## ozflea (Jan 12, 2012)

Well at least mine goes and goes well same as young Neils i built both 

McBob.


----------



## blsnelling (Apr 2, 2012)

I finally got around to making some good progress on this first 101B cart saw I started. I promised the owner I'd have it done by Spring, and Spring's here! I put it together before painting all the bolt on parts to make sure it ran good first. I was not disappointed! What a relief to see this old beast purring again. I've NEVER seen compression like this thing has. It takes two of use putting our feet on it to start it! Wow. Throttle response is lightning quick. I've already got it torn back down for paint. It won't be bad, since the case side cover and oil tank were painted before assembly. The engine stays intact. By the weekend, I hope to have it finished.

[video=youtube_share;ZWfh3dH0_Lk]http://youtu.be/ZWfh3dH0_Lk[/video]


----------



## blsnelling (Apr 2, 2012)

I put a kit in the Walbro SDC carb that came of the other SP125 that will be my personal saw. The fully adjustable L and H needles are a must have on a conversion like this. I'm amazed how easily this thing starts, and the electric like throttle response! The other one will probably get a Tilly HL carb and a lot more modding. The engine in this one is a stock rebuild 101B.


----------



## parrisw (Apr 3, 2012)

Wow, that sounds good. I need one! White finger here I come!


----------



## Ambull (Apr 3, 2012)

Good to see you back on it Brad. These are awesome saws. Wait till you make some cuts with it...... I highly recommend the drop start method.

[video=youtube;imVCsFHAx-g]http://www.youtube.com/watch?v=imVCsFHAx-g&list=UULrY2h5eSXnXFiDgP_AaseA&index=15&feature=plcp[/video]


----------



## Ambull (Apr 3, 2012)

blsnelling said:


> I finally got around to making some good progress on this first 101B cart saw I started. I promised the owner I'd have it done by Spring, and Spring's here! I put it together before painting all the bolt on parts to make sure it ran good first. I was not disappointed! What a relief to see this old beast purring again. I've NEVER seen compression like this thing has. It takes two of use putting our feet on it to start it! Wow. Throttle response is lightning quick. I've already got it torn back down for paint. It won't be bad, since the case side cover and oil tank were painted before assembly. The engine stays intact. By the weekend, I hope to have it finished.
> 
> [video=youtube_share;ZWfh3dH0_Lk]http://youtu.be/ZWfh3dH0_Lk[/video]



Good call holding out the starter handle when shutting is off. You can always tell the good motors by the way it snaps the handle back.


----------



## blsnelling (Apr 3, 2012)

I now know why guys do that. It REALLY grabs that handle when it shuts off.


----------



## Urbicide (Apr 5, 2012)

*McCulloch "Kick-Proof" starters*



blsnelling said:


> I now know why guys do that. It REALLY grabs that handle when it shuts off.



"Hello. Welcome to Shop Talk!":msp_biggrin:

A number of the very early McCulluch saws had a feature that was advertised as a "Kick-Proof" starter, just for that very reason. The first time I read that, I thought they were actually referring to some graceful person, like myself, blessed with big feet.  

It is a interesting, & definetely an old-school design. The starter pulley shaft fits inside a tightly wound coil spring. (This spring is completely separate from the regular starter spring every saw has.) The coil spring itself is made up of square wire & kind of resembles a speaker voice coil. This spring with the starter shaft, inside the center of it, fits tightly inside the starter housing. You may have to work at it to get it in place. The shaft will spin when the starter handle is pulled. If the saw should happen to kick back, the spring around the starter shaft tries to unwind itself. When it does, there is no physical space for this spring to really go anywhere, so it just clamps on down the starter shaft and against the starter housing. You might think of it as a sort of chain brake for the recoil. The big tip: If you ever have the pleasure of disassembling a Kick-Proof starter, you probably will not be able to pull the pulley & shaft assembly straight out of the housing. I did, on a 3-25, & stretched the snot out of the coil spring. You actually have to twist it out, and it will only twist in one direction. Which one? You'll see.


----------



## jra1100 (Apr 5, 2012)

Stupid question I'm sure, but if the 101 and the stock 123cc engine are the same displacement, why can't the stock engine be modified to the same specs as the 101. As you can tell I have never had mine apart to the extent that these have been. I'm not sure that I'd want all that much more power anyway, and as Brad pointed out, they are a bear to start anyway. JR


----------



## Jacob J. (Apr 5, 2012)

jra1100 said:


> Stupid question I'm sure, but if the 101 and the stock 123cc engine are the same displacement, why can't the stock engine be modified to the same specs as the 101. As you can tell I have never had mine apart to the extent that these have been. I'm not sure that I'd want all that much more power anyway, and as Brad pointed out, they are a bear to start anyway. JR



The 101 has a removeable head which allows for a large increase in compression. It also has more aggressive port timing from the factory. 
The 125 has a fixed head with a large combustion chamber and more sluggish port timing. Porting the old Macs is much different than 
porting a modern saw like a 372. They're a loop scavenge design reed-valve saw. The 125 can be made into a great runner but it will 
still have the compression issue.


----------



## stinkbait (Apr 5, 2012)

Jacob J. said:


> The 101 has a removeable head which allows for a large increase in compression. It also has more aggressive port timing from the factory.
> The 125 has a fixed head with a large combustion chamber and more sluggish port timing. Porting the old Macs is much different than
> porting a modern saw like a 372. They're a loop scavenge design reed-valve saw. The 125 can be made into a great runner but it will
> still have the compression issue.



As long as you wouldn' t have to raise the exhaust port to get the timing numbers you want, there shouldn't be any compression issues. You could always weld a pop on the 125 piston to move compression up as well. If I had more than one 125, I would port one.


----------



## ozflea (Apr 5, 2012)

Try starting a SP125 without using the decomp and you'll understand that both the SP125 and 101 are bears and big nasty bears at that 

McBob.


----------



## Ambull (Apr 5, 2012)

jra1100 said:


> Stupid question I'm sure, but if the 101 and the stock 123cc engine are the same displacement, why can't the stock engine be modified to the same specs as the 101. As you can tell I have never had mine apart to the extent that these have been. I'm not sure that I'd want all that much more power anyway, and as Brad pointed out, they are a bear to start anyway. JR



Also, the 101b has a steel sleeve, so it can be overbored like a car engine. There are aftermarket pistons up to .060 over which pushes the displacement to over 130 cc's. Overboring the cylinder is very easy because of the removable head. It does not require a bottom bore, which is much more difficult. Combustion chamber stays the same, so compression ratio goes up as well. One of my saws is .050 over, which is 129cc I think.


----------



## blsnelling (Apr 5, 2012)

Anyone have a flywheel key for a 125? How about a front lower AV mount, the one on the bottom of the wrap handle? I also need a coil for that will work on the 101 block.

The first saw is in primer. I'll be shooting the color here shortly.


----------



## Jacob J. (Apr 5, 2012)

blsnelling said:


> Anyone have a flywheel key for a 125? How about a front lower AV mount, the one on the bottom of the wrap handle? I also need a coil for that will work on the 101 block.
> 
> The first saw is in primer. I'll be shooting the color here shortly.



The flywheel key can be had at a hardware store.


----------



## ozflea (Apr 5, 2012)

Ambull said:


> Also, the 101b has a steel sleeve, so it can be overbored like a car engine. There are aftermarket pistons up to .060 over which pushes the displacement to over 130 cc's. Overboring the cylinder is very easy because of the removable head. It does not require a bottom bore, which is much more difficult. Combustion chamber stays the same, so compression ratio goes up as well. One of my saws is .050 over, which is 129cc I think.



Truth is they can be bored a bit further than that i have slugs here up to 110 thou with rings 
Thats how they grow to 133cc 

McBob.


----------



## jra1100 (Apr 5, 2012)

ozflea said:


> Try starting a SP125 without using the decomp and you'll understand that both the SP125 and 101 are bears and big nasty bears at that
> 
> McBob.



Now if that ain't the truth nothing is. I'm not sold on drop starting it, I did it once and it worked fine, tried again and near ripped my arm off. In the video he said to get it TDC, and perhaps that will help, I may need to have a few beers and screw up my courage. I'm not a small person either, and not real weak either. These are DEFINITELY not your average box store homeowner saws. Of course if your following this thread you already know all that. JR


----------



## Dennis Cahoon (Apr 5, 2012)

blsnelling said:


> Anyone have a flywheel key for a 125? How about a front lower AV mount, the one on the bottom of the wrap handle? I also need a coil for that will work on the 101 block.



Sure do!......How many do you want.......Hahahahahahaha!


----------



## blsnelling (Apr 5, 2012)

Dennis Cahoon said:


> Sure do!......How many do you want.......Hahahahahahaha!



Just one, lol. And throw a coil in there with it I've got one on this MC91 here, but it's a complete engine and I don't want to start scavenging parts off of it.


----------



## blsnelling (Apr 5, 2012)

2 hours in the over @ 170°F.


----------



## ozflea (Apr 6, 2012)

blsnelling said:


> 2 hours in the over @ 170°F.



Hate to be the bearer of bad news but unless you shave a few fins on top of the 101 head that SP125 cylinder cowl wont fit 
Did you try it on before painting it ?

McBob.


----------



## ozflea (Apr 6, 2012)

Dennis Cahoon said:


> Sure do!......How many do you want.......Hahahahahahaha!



Nice to see your following this thread Dennis ................ you must be lacking entertainment elsewhere haven't you got a Plastic Honda to play with ? he, he, he, he, he, he, he, he, he, he, he, he,


----------



## Brian13 (Apr 6, 2012)

That turned out really nice Brad!! Cant wait to see it come together.


----------



## Ambull (Apr 6, 2012)

Nice job on the paint. Looking good.


----------



## Ambull (Apr 6, 2012)

ozflea said:


> Hate to be the bearer of bad news but unless you shave a few fins on top of the 101 head that SP125 cylinder cowl wont fit
> Did you try it on before painting it ?
> 
> McBob.



I think that the cowl was on the saw when he got it, so either the fins have already been shaved, or for some reason it just fits.


----------



## blsnelling (Apr 6, 2012)

Ambull said:


> I think that the cowl was on the saw when he got it, so either the fins have already been shaved, or for some reason it just fits.



The cowl that was on the saw was in very poor condition. The holes where the upper AV bracket mounted were all busted out and put together with washers. This is a NOS one that I got with all the parts with these two saws. I did put it on before painting, but did not bolt it down. It looked tight, but looked like it would fit. I'll find out today.


----------



## Tzed250 (Apr 6, 2012)

Duhtaylz please!! What paint? Color code?


----------



## carym2a (Apr 6, 2012)

blsnelling said:


> 2 hours in the over @ 170°F.



Dang, sure is purdy


----------



## blsnelling (Apr 6, 2012)

What a relief! When you're working with a repainted saw like this, you don't want to have problems with it, and have to keep taking it back apart. She fired right up, runs great, kill switch works, oiler works.... Amazing! I couldn't be happier. I have one thread to repair on the recoil. I'd like to accent the logo on it while I have it back off. It could also use a new spark plug cover and pull handle. I believe the owner has a newish handle to install on it when he gets it back.

[video=youtube_share;jmGycpqvpCU]http://youtu.be/jmGycpqvpCU[/video]


----------



## Anthony_Va. (Apr 6, 2012)

Man that is just a thing of beauty! :msp_wub:

You've outdone yourself on this one ole boy.


----------



## leeha (Apr 6, 2012)

Looks great Brad. Ya done good.



Lee


----------



## Ambull (Apr 6, 2012)

That saw is really sharp. I'll bet it cuts pretty well too.

Good job man.


----------



## gink595 (Apr 6, 2012)

Beautiful saw, great build thread too


----------



## Dennis Cahoon (Apr 6, 2012)

Nice looking saw Brad......but the blue isn't the right blue......just nit-picking!


----------



## HEAVY FUEL (Apr 6, 2012)

nice job!


----------



## ozflea (Apr 6, 2012)

Looks great Brad you have done a rather nice job like all you do on saws 

McBob.


----------



## McC (Apr 6, 2012)

The last video is 1:01 long! Nice detail.
Scott


----------



## parrisw (Apr 6, 2012)

Looks real nice Brad!!


----------



## blsnelling (Apr 6, 2012)

Thanks guys. Something like this is definately more rewarding than a new saw. It's a whole different kind of cool


----------



## Dennis Cahoon (Apr 6, 2012)

Why didn't you paint the the starter housing metal flake blue like original Brad?


----------



## blsnelling (Apr 6, 2012)

Dennis Cahoon said:


> Why didn't you paint the the starter housing metal flake blue like original Brad?



I've never seen an original. I like the sounds of that! I'll try to make that happen when I get around to doing mine.


----------



## ozflea (Apr 6, 2012)

blsnelling said:


> I've never seen an original. I like the sounds of that! I'll try to make that happen when I get around to doing mine.








I have a few starters complete with this sticker in my vault 

McBob.


----------



## blsnelling (Apr 6, 2012)

ozflea said:


> I have a few starters complete with this sticker in my vault
> 
> McBob.



Very nice. I like that.


----------



## heimannm (Apr 7, 2012)

e-bay seller GM??? in Vermillion, OH has the spark plug covers, not unreasonable on the price.

Looking good by the way. I think Dennis was pulling your leg on the starter cover paint, look again at his photo...

Mark


----------



## blsnelling (Apr 7, 2012)

heimannm said:


> I think Dennis was pulling your leg on the starter cover paint, look again at his photo...
> 
> Mark



Hahahaha. Yes, he got me


----------



## Dennis Cahoon (Apr 7, 2012)

I wouldn't pull your leg Brad!.......Hahahahahahaha!

Now this is a stock 101B starter housing. Bottom right.....flag and stars on the starter, starter housing, candy apple blue paint.


----------



## ozflea (Apr 7, 2012)

The starter spring housing and outer cover on these are like a royal blue and the cover has no raised Mcc embossed lettering just a smooth flat surface like on the early 1-40's 

McBob.


----------



## Tzed250 (Apr 7, 2012)

S


Tzed250 said:


> Duhtaylz please!! What paint? Color code?



opcorn:


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## mdavlee (Apr 7, 2012)

It looks awesome. I still want to run one with the 101 in it with a regular 125 to see the difference.


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## cpr (Apr 7, 2012)

Looks awesome Brad. I've said it before and I'll say it again, I wish I had the time to make mine as beautiful as that. I just don't get the shop time. If did that, my builds would take 2 years instead of 8 months, lol. Maybe when I do the other 101 in a 797 I'll paint it...

Vid in the wood, puhleeze!


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## blsnelling (Jun 4, 2012)

I finally bought a carb for my saw. It's a Tilly 360A built by the late EC Birt. It's a stage three blueprint with all the bells and whistles. The velocity stack was cememted on and was machined for smoothness with the throttle bore. It was built for a 100 to 125 cc motor.


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## heimannm (Jun 4, 2012)

It will be interesting to see how that fits "under the hood".

Mark


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## leeha (Jun 4, 2012)

heimannm said:


> It will be interesting to see how that fits "under the hood".
> 
> Mark



Oh it will fit. Not sure on the intake Brad is using.
I'm curious to see if Brad encounters the same running
problems i'm having with my 101 with a HL360A carb.



Lee


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## cpr (Jun 6, 2012)

The Saw Gods must be against us Lee. The BDC still won't behave either.


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## burl1984 (Mar 17, 2014)

I'm having trouble getting my NOS 125/101b started. I have basically sourced all my parts NOS from ebay and some other sources. There are only a few parts that are not NOS but I did re-furbish the used parts as best I could. The saw was running a few weeks ago until the supposed NOS crank decided to strip and blow out at the keyway instead of the keystock itself on the flywheel. I have recently installed another crank and re-assembled the saw. Now all I can get the thing to do is POP every once in a while. It seems to want to flood super easy and after clearing the flooding issue it seems starved for fuel. If I choke it, it instantly floods. The carburetor is a 1972 BDC14. Any thoughts?

Thanks,

Burl


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## 54stude (Mar 17, 2014)

Was the carb nos? Could it have been modified for alcohol? If so, it might be hard to regulate it down enough for gas.


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## 2dogs (Mar 18, 2014)

I have a friend with a 101b NOS motor and he is looking for a chassis to put it in.


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## burl1984 (Mar 18, 2014)

The carburetor was used, how would I identify if it was modified for alky? I re-tested today for pressure and vacuum and it's still good on both. It's got super high compression as well, way more than my 3120xp.
I may order another BDC14 carburetor and re-build it as well to trouble shoot.


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## Jacob J. (Mar 18, 2014)

The BDC14 wasn't even really a great carb when they were brand new. You might have much better luck with a large bore Tillotson or Mikuni.


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## 54stude (Mar 18, 2014)

If you screw the high jet all the way in to close it off, can you get it to start and idle good using the choke to start it?


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## burl1984 (Mar 18, 2014)

The engine is in disassembly mode right now from the pressure/vacuum tests. I'll try the screw in the high method tomorrow. What's the ball park I should be in for turns out on the low for initial settings?


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## 54stude (Mar 18, 2014)

Try 1/2 or 1. And you should need some choke to start the saw cold. Once it starts and idles on the low. Turn out the h jet to tune it to be rich. But clean up when loaded in a cut. There are some good carb tuning threads here or on as if you need tips.


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## burl1984 (Mar 18, 2014)

Ok thanks for the info, I'll try that tomorrow upon re-assembly.


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## 54stude (Mar 19, 2014)

Jacob J. said:


> The BDC14 wasn't even really a great carb when they were brand new. You might have much better luck with a large bore Tillotson or Mikuni.



Is there a snowmobile, watercraft, chainsaw, or bike carb that would be preferred in this application? Something with a 32 or 34mm Venturi maybe?


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## Jacob J. (Mar 19, 2014)

54stude said:


> Is there a snowmobile, watercraft, chainsaw, or bike carb that would be preferred in this application? Something with a 32 or 34mm Venturi maybe?


There is, I'd have to do some research on it. All of the long time kart guys I've worked with say that the large bore, single pumper early BDCs are poor performers. I tried a 14 once and it was just garbage.


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## burl1984 (Mar 19, 2014)

I re-assembled the saw this evening and tried the all the way in on the high and .5-1.0 turns out on the low. The saw pops a little longer than before the pressure/vacuum tests but still doesn't want to idle. It seems way rich still. If i turn the low in any further it won't pop at all. I'm thinking the carburetor may have been modified for alky as mentioned in an earlier post. I have a NOS carburetor coming. I would be interested in a jetski carburetor if it was easily adaptable.


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## ozflea (Mar 19, 2014)

Jacob J. said:


> The BDC14 wasn't even really a great carb when they were brand new. You might have much better luck with a large bore Tillotson or Mikuni.



What a load of chodswhople there fine if you know how to set them up


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## burl1984 (Mar 19, 2014)

I have a used BDC16 and a rebuild kit as well. I was kinda not wanting to run alky to start with.


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## cpr (Mar 20, 2014)

Stick with it. The single-pumper BDCs are finicky around lever hight. If it's flooding, set it at even with carb housing and adjust from there. There's no BDC voodoo, just patience.


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## heimannm (Mar 20, 2014)

I would like a bowl of that chodswhople to go with my soba noodles please.

My 101 did not run very long before ingesting the needles from the pin bearings but the BDC seemed to work just fine.

As Sir Charles says, patience is a virtue.

Mark


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## burl1984 (Mar 21, 2014)

burl1984 said:


> The carburetor was used, how would I identify if it was modified for alky? I re-tested today for pressure and vacuum and it's still good on both. It's got super high compression as well, way more than my 3120xp.
> I may order another BDC14 carburetor and re-build it as well to trouble shoot.


Compression is 150~ psi on the MC and the OEM 3120 is 125~ psi. So I guess my use of the term super high compression could be interpreted many ways.

cpr, I'm a super noob when it comes to setting lever height. I'm not sure what you mean by level with the housing. Is there a thread that specifically goes into detail about this procedure?

Thanks,

Burl


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## burl1984 (Mar 21, 2014)

http://www.arboristsite.com/community/threads/mcculloch-carburetors.122113/

Is post #11 what is meant by setting the lever at the height of the housing?


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## cpr (Apr 1, 2014)

Yes


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## burl1984 (Apr 8, 2014)

I got the NOS BDC14 in the mail and checked it out. The only thing that looked like it needed to be replaced was the duckbill valve. The lever height on the NOS carburetor was a ways above the height of the housing. I did not adjust it because I figured the supposed factory setting was adequate. The result are the same when trying to start the saw it still only pops a few times and either floods easily or doesn't seem to be getting the proper amount of fuel.

I'm wondering if I should use a different head. The one I have on the saw currently was labeled as NOS High Compression option. Terry Ives a Kart specialist recommended using a non-high compression head in the chainsaw application to get higher RPM's. I'm wondering if the High Compression head would work better with Race Fuel or an alky blend with the BDC16 carburetor.

I have the standard compression head but it's not a NOS product. I did mill out an tap it for a compression release valve so it should be just a matter of dis-assembling the saw to swap out the head and re-torque the head bolts to try this new configuration.


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## nmurph (Apr 9, 2014)

No, you need to follow the help you've been given. Set the lever flush with the carb body as shown in the second pic in the link you referenced.


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## burl1984 (Apr 9, 2014)

I'll try to get everything re-setup this weekend and give it another pull!


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## sawfun (Oct 19, 2016)

burl1984 said:


> I got the NOS BDC14 in the mail and checked it out. The only thing that looked like it needed to be replaced was the duckbill valve. The lever height on the NOS carburetor was a ways above the height of the housing. I did not adjust it because I figured the supposed factory setting was adequate. The result are the same when trying to start the saw it still only pops a few times and either floods easily or doesn't seem to be getting the proper amount of fuel.
> 
> I'm wondering if I should use a different head. The one I have on the saw currently was labeled as NOS High Compression option. Terry Ives a Kart specialist recommended using a non-high compression head in the chainsaw application to get higher RPM's. I'm wondering if the High Compression head would work better with Race Fuel or an alky blend with the BDC16 carburetor.
> 
> I have the standard compression head but it's not a NOS product. I did mill out an tap it for a compression release valve so it should be just a matter of dis-assembling the saw to swap out the head and re-torque the head bolts to try this new configuration.


I know this is an old thread, but in case anyone could use some info, the lever on mine is set at .010 down and try different stiffness Springs to eliminate the flooding. I did this and mine works fine.


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## blsnelling (Oct 19, 2016)

I'm a VERY, VERY bad man. The parts for my 101 are all still setting in a box, just waiting to be put together


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## Stihl 041S (Oct 19, 2016)

Bad Bradley!!!!!
Bad Bad Bradley!!!!


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## sawfun (Oct 19, 2016)

Brad, it took me a while to get motivated as well.


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## heimannm (Oct 20, 2016)

I have two 101 powered saw that are non-running at the moment. Just no time for the fun things in life right now.

Mark


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## JonCraig (Oct 21, 2016)

blsnelling said:


> I'm a VERY, VERY bad man. The parts for my 101 are all still setting in a box, just waiting to be put together



I wasn't here for the first build, but read the whole thread & loved it--especially the completed pics.

Now I learn that you never finished yours?! C'mon, Brad! Knock it out this weekend!


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## Ambull (Oct 21, 2016)

JonCraig said:


> I wasn't here for the first build, but read the whole thread & loved it--especially the completed pics.
> 
> Now I learn that you never finished yours?! C'mon, Brad! Knock it out this weekend!



I own that saw, and it still looks great. I have only made a few cuts with it. It is really difficult to start. The tank leaked, but I sealed it up with Casewell Tank Sealer, and it has been good ever since. A little bit of the paint peeled on the tank, and I touched it up so that it is barely noticeable.


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## blsnelling (Oct 21, 2016)

Ambull said:


> I own that saw, and it still looks great. I have only made a few cuts with it. It is really difficult to start. The tank leaked, but I sealed it up with Casewell Tank Sealer, and it has been good ever since. A little bit of the paint peeled on the tank, and I touched it up so that it is barely noticeable.


That really bummed me out when you showed me where the tank seam leaked 

Any idea why it's hard to start? Carb issue?


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## Ambull (Oct 22, 2016)

blsnelling said:


> That really bummed me out when you showed me where the tank seam leaked
> 
> Any idea why it's hard to start? Carb issue?



The freakin compression is so high, that I can barely get it to turn over. Every time I try to start it I think that I will break the starter or pull cord, or my arm for that matter. It will start on the third or fourth time that I get it to turn over for more than one revolution. Nothing at all wrong with the carb.


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## sawfun (Oct 22, 2016)

Ambull said:


> The freakin compression is so high, that I can barely get it to turn over. Every time I try to start it I think that I will break the starter or pull cord, or my arm for that matter. It will start on the third or fourth time that I get it to turn over for more than one revolution. Nothing at all wrong with the carb.



I had a 790 that was like that and I never did figure out why. Oh well, poor Aaron has that saw now.

My 101's both seemed impossible to start, as did a ported 880 I had. But after starting them 5 or 6 times they seemed to get easier and the just stayed that way. So maybe it's an initial break in? I dunno. Maybe I just learned how to start them or grew stronger overnight?


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## James Ragz (Sep 4, 2017)

I'm new to ArboristSite, I joined cause I like what I see, mostly saw talk. I just bought a 101D and I'm having it bored out, well I got to looking at the block and noticed it's got the two boost port dimples on the side of it. Now I've been watching videos of The Chainsaw Guy and he keeps pointing out these dimples mean the block is a "101B" so I'm all mixed up, this is my first 101 engine, from what I've read, all 101's have the same bore,stroke & horsepower . What makes the 101B The Crown Jewel.


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## sawfun (Sep 4, 2017)

James Ragz said:


> I'm new to ArboristSite, I joined cause I like what I see, mostly saw talk. I just bought a 101D and I'm having it bored out, well I got to looking at the block and noticed it's got the two boost port dimples on the side of it. Now I've been watching videos of The Chainsaw Guy and he keeps pointing out these dimples mean the block is a "101B" so I'm all mixed up, this is my first 101 engine, from what I've read, all 101's have the same bore,stroke & horsepower . What makes the 101B The Crown Jewel.


Someone will likely correct me, however, I believe all 101 blocks except the MC versions are the same. The "D" version has the bigger end of the crank for the larger kart clutches and won't work with a saw clutch unless you somehow made your own. That engine will work fine with a standard size PTO end crank like from any other Mac kart engine, 797, or 125. by the way, welcome aboard.


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## p61 western (Mar 22, 2019)

blsnelling said:


> I'm a VERY, VERY bad man. The parts for my 101 are all still setting in a box, just waiting to be put together


I know it's a really old thread, but did you ever build your 125? If so is there a thread here on it? This was a great thread btw.


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## blsnelling (Mar 22, 2019)

p61 western said:


> I know it's a really old thread, but did you ever build your 125? If so is there a thread here on it? This was a great thread btw.


I have not


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## p61 western (Mar 22, 2019)

blsnelling said:


> I have not


Well hopefully you get around to it soon. I just got a 125c, and like you were at the beginning of this thread, I'm a Mac newb lol. I got a thread going over on the other site. Would be cool to see a thread on you building your 125.


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## 100 cc plus saw (Jan 18, 2020)

Any 101b for sale always wanted one love the sound I got 790 that I want to put 101b in could this be my time


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## Yotaismygame (Jan 18, 2020)

100 cc plus saw said:


> Any 101b for sale always wanted one love the sound I got 790 that I want to put 101b in could this be my time



i know a guy selling a sp125 with the cart motor. Wants lots of $$$. He sent it down to the chainsaw king to work on who posted a video about it


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