Mcculloch sp125/101b kart saw build thread

[Bigmac]

I am now having the same problem others have had with this carb, rich midrange, there are some well documented fixes for it! I am going to try the feed restriction for the midrange and see how that works, it’s just a copper wire in the transition circuit, kart guys say it’s a must do

 

[Bigmac]

Had some collateral damage today!
Recoil rope broke, it was new, so I threw on a different one.
And a nos clutch explodedIt’s been rough! Lol at least I got it safe and fat!

 

[Lee H]

YIKES, I wouldn't want to be around when that clutch come apart at 10K

 

[Bigmac]

YIKES, I wouldn't want to be around when that clutch come apart at 10K

It was surprising, but the drum took keep everything together! Now I am wondering if these 4 shoe clutch’s are junk? They are cheaper than the 3 shoe, maybe this was a fluke. Has anyone else had this happen, clutch has maybe a half hour cut time. It happened on the first cut with this wb.

 

[jacob j.]

It was surprising, but the drum took keep everything together! Now I am wondering if these 4 shoe clutch’s are junk? They are cheaper than the 3 shoe, maybe this was a fluke. Has anyone else had this happen, clutch has maybe a half hour cut time. It happened on the first cut with this wb.

My dad had some of the four-shoe clutches with a lot of hours on them, so I don't think they're completely junk, but the three-shoe clutches are
better in my mind because they're serviceable. I've got a large box full of old clutches my dad ran and he has both three and four shoe clutches in there
that are completely worn out.

 

[sawfun]

It was surprising, but the drum took keep everything together! Now I am wondering if these 4 shoe clutch’s are junk? They are cheaper than the 3 shoe, maybe this was a fluke. Has anyone else had this happen, clutch has maybe a half hour cut time. It happened on the first cut with this wb.

It would seem like the clutch drum acts as a make shift scattershield. That and the clearance was so little the parts didn't get much space to gain velocity. I've always thought the 4 shoe clutch looked a good deal stronger.

 

[Bigmac]

Thanks for the input guys, maybe this clutch was a fluke.

Fired up the saw on lunch break and the feed restrictior really helped, but my nos box muffler came apart!! The tube for the mount shot off!

time for a box gem muffler

 

[Steve]

Thanks for the input guys, maybe this clutch was a fluke.

Fired up the saw on lunch break and the feed restrictior really helped, but my nos box muffler came apart!! View attachment 211955 The tube for the mount shot off!

time for a box gem muffler

You have had a hell of a time with new parts!

 

[Bigmac]

You have had a hell of a time with new parts!

Haha! Yes! Some odd failures!

 

[Lee H]

Stock muffler is no where near enough for a 101 motor. If I were to use a stock muffler
I would have added another outlet like the original or a Gem type muffler. Those motors
need to breath. Here is one I did on a 101 motor. I opened up the spark arresters as well.

 

[Bigmac]

View attachment 212027 Stock muffler is no where near enough for a 101 motor. If I were to use a stock muffler
I would have added another outlet like the original or a Gem type muffler. Those motors
need to breath. Here is one I did on a 101 motor. I opened up the spark arresters as well.

That’s cool lee, I had the baffle out so I figured it would be fine, was planning on testing the box vs gem box and maybe a kart puck muffler to see if he differences. But that’s out now! Lol

The muffler had flex even with the muffler baffle out, so in hindsight that was a sign, it didn’t do that with the sdc and stock reeds, she so definitely flowing more air now, the box gem will be next, just don’t have it yet. Lol I didn’t think it would blow apart!

 

[Bigmac]

View attachment 212027 Stock muffler is no where near enough for a 101 motor. If I were to use a stock muffler
I would have added another outlet like the original or a Gem type muffler. Those motors
need to breath. Here is one I did on a 101 motor. I opened up the spark arresters as well.

Lee, how did the saw end up running? Is that the one you build a custom manifold and tilly?

 

[Lee H]

Lee, how did the saw end up running? Is that the one you build a custom manifold and tilly?

It is the saw. I need to get it back on the bench. It never ran right. The HL360 never
performed as I thought it would. I was going to try the WB carb like yours. I also did
a electronic ignition for it but it is way advanced now. Going to go back to points.

 

[Bigmac]

It is the saw. I need to get it back on the bench. It never ran right. The HL360 never
performed as I thought it would. I was going to try the WB carb like yours. I also did
a electronic ignition for it but it is way advanced now. Going to go back to points.

I have never been a member of as, but I remember that build along with others and always wanted to know how it ended up. I appreciate the builds you have done and have used many for reference.
Were you running the chip ignition? I remember mcbob using a ryobi ignition on the McCulloch laminate, but I have never found a write up on that swap. I am running a chip on this wb, I have thought about messing with the flywheel key to adjust the timing a hair too.

 

[Bigmac]

I ordered up two new 4 shoe clutches, hoping they hold up! Can’t find a gem box on eBay right now, so that could take a while

 

[Lee H]

A few years ago I bought a 101 powered 125 off ebay. I went and changed the fan housing to chrome
and noticed an odd ignition set up. Did some research and found the guy had used a Poulan electronic
coil and put it on the 125 coil lamination. I did this as well but the timing is so advanced it is nearly
impossible to start. I'm just going to go back to points when I get some time. I never liked the chips.
I had a 790 Mac with a chip and it to was way advanced.

 

[jacob j.]

I have never been a member of as, but I remember that build along with others and always wanted to know how it ended up. I appreciate the builds you have done and have used many for reference.
Were you running the chip ignition? I remember mcbob using a ryobi ignition on the McCulloch laminate, but I have never found a write up on that swap. I am running a chip on this wb, I have thought about messing with the flywheel key to adjust the timing a hair too.

Bob did a write up on the Ryobi weed eater ignition but that was around the time that AS had been hacked and some content was lost.

Several of his other write-ups were also deleted, which is too bad because he had some really good content in there. He even posted
pictures of a 101 build-up that had a custom-machined head and three carbs with external transfers that was pretty wild.

 

[Bigmac]

I have done a chip on 2 saws, and left the point intact, and could switch back and forth to see what I liked better, I must not have the 5° flywheel because I couldn’t tell the difference. I have heard the flywheel vary a fare amount , like some 5° flywheel wheels go from 3.5-7.5° so those 7.5° with a chip or laminate swap would be a killer! The standard flywheel is probably the best for ignition swaps

 

[Bigmac]

Bob did a write up on the Ryobi weed eater ignition but that was around the time that AS had been hacked and some content was lost.

Several of his other write-ups were also deleted, which is too bad because he had some really good content in there. He even posted
pictures of a 101 build-up that had a custom-machined head and three carbs with external transfers that was pretty wild.

Ya it’s too bad that info is gone, his website had great info too! Condensers seen to harder to find, and also getting pricey, not sure if there is a good alternative either

 

[jacob j.]

Ya it’s too bad that info is gone, his website had great info too! Condensers seen to harder to find, and also getting pricey, not sure if there is a good alternative either

Terry Brannon (Cascade Saw) did a good write up on capacitors that would work in place of condensers. The capacitors can be soldered in
and would (potentially) be a permanent fix. I can't find the info now and Terry's Cascade Saw page is down. The write up was on AS - I'll
see if I can find a cached copy.