Building a SP125C / 101B Kart Saw

[ozflea]

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

McBob.

Just in case you missed it Dennis see the decompressor

 

[Dennis Cahoon]

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]

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]

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

Lee

 

[watsonr]

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.

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]

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]

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]

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

 

[24d]

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.]

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]

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]

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]

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]

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]

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]

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.]

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]

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.]

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]

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