McCulloch Chain Saws

[Eccentric]

Pulled out my 650 today. I haven't hardly looked at it since I bought it a year or so ago. Pulled the air filter and found out that it has the tillotson HL carb with choke. I did a compression check and found that it has just a little over 160psi. I'm happy with that number. I pulled the clutch cover and painted a mark on the clutch drum and sprocket to use as a reference while figuring out what gearcase ration I have. Turns out that I have a 2:1 reduction. The sprocket is an 8 tooth 1/2" pitch. I have a 32" mac hardnose bar with a brand new mac 1/2" chain to go on it. The only thing wrong with the saw that I know of is the broken wrap handlebar.

Awesome! You have the fast ratio, the 'better' carb, and an engine in great shape. Can't beat that. My 650 is a 3/1 saw and I'd prefer it to be 2/1. I have a nice 26" McCulloch hardnose and a loop of 1/2" chain. It's my ripping/blocking saw. I got it from the son of the original owner. He told me that his dad had bought the saw new with a 36" bar, but "traded in" that B/C for a 26" B/C from the dealer as it was too awkward with the 36" bar.:bang:

I just recently got an NOS 32" McCulloch hardnose and will probably outfit it with .404 and swap on a .404-8 sprocket. I'll REALLY be wanting the 2/1 gearset when I do that methinks. Maybe I'll get lucky and find some good 1/2" for that bar instead. I can't remember if the spur on that saw is 1/2-7 or 1/2-8...

 

[stinkbait]

Awesome! You have the fast ratio, the 'better' carb, and an engine in great shape. Can't beat that. My 650 is a 3/1 saw and I'd prefer it to be 2/1. I have a nice 26" McCulloch hardnose and a loop of 1/2" chain. It's my ripping/blocking saw. I got it from the son of the original owner. He told me that his dad had bought the saw new with a 36" bar, but "traded in" that B/C for a 26" B/C from the dealer as it was too awkward with the 36" bar.:bang:

I just recently got an NOS 32" McCulloch hardnose and will probably outfit it with .404 and swap on a .404-8 sprocket. I'll REALLY be wanting the 2/1 gearset when I do that methinks. Maybe I'll get lucky and find some good 1/2" for that bar instead. I can't remember if the spur on that saw is 1/2-7 or 1/2-8...

I was surprised to see the 1/2" 8 tooth sprocket. These saws must be a beast to pull that. One thing that I don't understand is why the bore on these HL carbs are so small. It's actually smaller than the bore of the ZAMA on my Pro Mac 800.

 

[Eccentric]

I was surprised to see the 1/2" 8 tooth sprocket. These saws must be a beast to pull that. One thing that I don't understand is why the bore on these HL carbs are so small. It's actually smaller than the bore of the ZAMA on my Pro Mac 800.

Don't worry about it my friend. They flow plenty of air. HL's with the same throttle and venturi bore measurements on your 87cc McCulloch 650 were used on 123cc McCulloch 797's. The smaller bore size gives better fuel atomization and throttle response anyways. The sharp 90degree intake bend in the carb box casting is the real restriction in these saws. My McCulloch 550 and 790 (99 and 103cc) breath just fine with these carbs. I swapped HL's onto both of them (and my 650) in place of the flatbacks.

 

[RandyMac]

Back in '76, on a stream clearance project we came across a log that was too much for the 48" bars on the 660s.
We borrowed a 60" Cannon meant for the SP125s that were filtering in as replacements for the 660s.
We put an 8 tooth .404 sprocket on a 3 to 1 660. We got in two days of bucking before we got caught and the overhead took the Cannon away from us. Pretty funny that they thought they needed to replace the 660s with SP125s.

 

[Michigan Muscle]

There's a 'duckbill valve' inside the cap. I don't know if the McCulloch duckbills are available anymore. The Homelite duckbills are being reproduced by Stens and Oregon. Not sure if they can be used in the McCulloch 10-series caps. I know they're not the right size for the large frame Mac caps (but I'm going to try to make that work). You can use a Homelite Super XL cap on the 10-series saws if you have to (but it don't look right) if you NEED to cut right now. I've done that before.



There are a few used and NOS 24" large frame McCulloch bars on feebay right now. I have an 'extra' 24" bar and loop of .404 chain, but it is tenatively spoken for already as part of a trade. I'll let you know if the other guy backs out.

Sounds good - thanks a lot. Much appreciated! I'll hop on feebay and check it out tonight.

 

[Eccentric]

Back in '76, on a stream clearance project we came across a log that was too much for the 48" bars on the 660s.
We borrowed a 60" Cannon meant for the SP125s that were filtering in as replacements for the 660s.
We put an 8 tooth .404 sprocket on a 3 to 1 660. We got in two days of bucking before we got caught and the overhead took the Cannon away from us. Pretty funny that they thought they needed to replace the 660s with SP125s.

If I had a 43-60" bar for my 650 I'd be more excited about the 3/1 gearbox. Got outbid on a couple big Mac RN's like that a couple weeks ago (48" and 60"....called 54" and 64" by the seller). I agree about the 660/125 thing. A gear drive like that is more suitable for long bucking runs with a 60" bar than a big DD saw anyways.

 

[db456]

My 650 was all apart like that last week. Got it back together and running yesterday. Had to swap in a good carb- waiting on the rebuild kit. It has the tillotson and 2 to 1 gears.

 

[a. palmer jr.]

I got some grief a while ago for stating that 24" McCulloch sprocket nose 10-series bars weren't hard to find. NOT talking about the 'universal' bars with the adaptors, which CAN still be used without any real issue. Talking about 'genuine' McCulloch branded Windsor TMX mount bars here. A quick completed listings search fo "McCulloch bar" (to find the RN bars I linked to in my last post) found THIS seller, who currently has THIS bar and chain set for sale. A decent price considering everything, and something I probably shouldn't list publically as I want to buy one when I'm able. However, since I WON'T be able to do so for a LONG time...................here it is.

NEW McCULLOCH/WINDSOR 24" BAR/CHAIN COMBO 3/8P 058G 81DL FITS PM10-10S/PM700 | eBay

They sold a bunch of NOS Mac 26 and 36 inch bars at an auction I went to. I only bought one but sold it already, wish I'd bought them all, mine was a 26 incher. I sold it for $50 plus shipping. I would like to have kept it but don't need anything that big.

 

[homelitejim]

I will be heading out in the morning to pick up 2 big McCulloch chainsaws, the individual I am getting these saws from has no clue as to what models they are only that they have bars as long as his outstretched arms. He also said there are 5 saws there so not sure what the other three are.

 

[fir]

hers my pro mac 10-10 Im going to us it for tree work this weekend boss thinks im nuts.View attachment 228837View attachment 228838View attachment 228839View attachment 228840

 

[Eccentric]

hers my pro mac 10-10 Im going to us it for tree work this weekend boss thinks im nuts.View attachment 228837View attachment 228838View attachment 228839View attachment 228840

Good for you! I used to have one just like that. Traded it to another AS member for a Homelite project of his that I'd been wanting for a while. He still has it. You're not nuts, you're nostalgic. MANY tree jobs were done with those saws....

 

[homelitejim]

Well, the saw gods frowned on me today, I did pick up 2 yellow saws but only one was a Mac. I got a fairly decent 4-30 and a Sears 355-83130 or something like that.

 

[HeRoze]

I'm stumped. Got a d-36 back together. replaced a few parts (bearings/seals, starter gizmo, trigger, fuel lines w/a rigged pick up line), took apart and cleaned everything down to piece-parts (carb, reeds) and repaired the clutch cover. Got a nice blade on her.

it gets hot spark. it will NOT turn over. starter seems to be engaging fine. shot prime in the carb, and then finally in the chamber. still no luck. any idea is a good idea right now.... vic

 

[RandyMac]

Timing?

 

[Warped5]

Timing?

:agree2:

 

[HeRoze]

alright... I can see that. I made my best guess based on the B&W scanned manual, so I may have set it to the wrong point. I finally figured out how to set it exactly where I 'think' it should be... where should it be set?

it opens right as the leading edge of the magnet passes the trailing edge of the coil, unless it slipped somehow.


Here's a pic... this is about 2 degrees past when it opens.

View attachment 228954

 

[watsonr]

:agree2:

yep, timing.

Should open just as you say and should be about .018-.021 gap on the points. A little less will advance the timing, a little more retard it. Check the plug gap or even give it a new plug. Whats the compression?

 

[HeRoze]

coil isn't on upside down or something else stupid???

 

[cpr]

Nope. Points. 019, module .010-.012, plug. 020. Something else is amiss.

 

[HeRoze]

here's what I am seeing when I turn the FW nice and slow CCW. Points are cycling.... I'm using a 1KOhm scale on an analog VOM. I pulled the ground off the laminates and am metering between it and the chassis. Double-checked for good connections on the probes.

right where the pic shows ~ 8 degrees BTDC (a guess, but serves as a reference)
8 BTDC - OPEN
18 ATDC - CLOSED
20 ATDC - OPEN
45 ATDC - CLOSED
47 ATDC - OPEN
55 ATDC - CLOSED
56 ATDC - OPEN
58 ATDC - CLOSED for the rest of the way around back to 8 BTDC

gotta see if I dropped one of my magnets in the back of the FW when it was on the bench... any other culprits, or is this normal somehow?