McCulloch Super Pro 125c build thread

[sawfun]

I have the mate to that one. Bought it over a year ago. At the time the seller had two.
I bet this is the one I didn't buy. Have seen it on ebay a couple times since. Nice motor
but crank needs to be changed for a saw motor.

Just run nitro and a bigger clutch.

 

[Al Smith]

So what's the deal with a 101 crank?I just assumed it would be like the 125 c with a tapered unkeyed power side . If it was a straight shaft you'd have to get real creative to adapt a komet type clutch and spur of some kind .Thinking out loud I've got a new never used 125c clutch,I'm not certain if the spinder could be bored out and a key way broached in it or not .
Fact I think I have one or two 125 clutches the spinder got cracked which I assume was caused by running a drum that was worn concaved because the bushing or needle got worn out .That could cause the shoes to engage misaligned .It's only a guess on my part .

 

[Al Smith]

You can get real creative on this stuff.Depends on how much junk you have laying around,skill set as a machinest with the tools and a vivid imagination .Nothing is impossible but some times it just takes a long time to do .

 

[sawfun]

The 101 cranks can be different. A 101b is pretty much like a 797 crank, if memory serves. The 101c has opposite direction threads on the PTO side, and the 101D has a large, non - tapered PTO side.

 

[Al Smith]

Okay now did the 101c come it counter rotation models ?I don't know myself .
Again thinking out loud .Could it possibly be the straight shafts might be the same size as the screw on clutches used on some of the old gear drives ? Even if so I wouldn't think they would be easy to find .I'm just pulling stuff out of thin air because I don't know .

 

[sawfun]

Okay now did the 101c come it counter rotation models ?I don't know myself .
Again thinking out loud .Could it possibly be the straight shafts might be the same size as the screw on clutches used on some of the old gear drives ? Even if so I wouldn't think they would be easy to find .I'm just pulling stuff out of thin air because I don't know .

The 101D cranks I've seen are always in complete shortblock and quite a few have been for sale on EBay. They don't seem anymore rare than the other variants. As far as geardrive shafts go, the 895 style gear drives have a regular tapee crank. Are you speaking about the two man or 73/77 cranks not having the taper?

 

[Lee H]

So what's the deal with a 101 crank?I just assumed it would be like the 125 c with a tapered unkeyed power side . If it was a straight shaft you'd have to get real creative to adapt a komet type clutch and spur of some kind .Thinking out loud I've got a new never used 125c clutch,I'm not certain if the spinder could be bored out and a key way broached in it or not .
Fact I think I have one or two 125 clutches the spinder got cracked which I assume was caused by running a drum that was worn concaved because the bushing or needle got worn out .That could cause the shoes to engage misaligned .It's only a guess on my part .

The one in the pic has a straight crank, Not tapered. It is also threaded in the end so I
don't think it can be turned down and have any left for the threaded end like a tapered
crank.

 

[Al Smith]

My reference was a 650 gear drive ,it has a straight shaft .They are relatively rare ,fact mine is the only one I've ever seen . 87 cc ,two to one reduction circa 1966 . It's a long clutch drum with a gear on the end that is the first part of the gear drive assembly . I'm not sure if I have a picture or not .---second thought,I just looked it up,same clutch as a 250.screw on .its a turn down shaft .
Hmm now I wonder if the kart engine has the same turned down shaft threaded on the end ,don't know but if it does ,they made a zillion 250's .I think I have 4 of them .

 

[Lee H]

Al I also have a 650 and a 660 gear drives.

 

[Al Smith]

That's three of them then If I'm not mistaken Mike Acres has one .He's got about 500 saws though .Well then after saying that do you know if the shaft size is the same as that straight shaft 101 ?I don't have a kart engine and I don't know .Well I have a West Bend 580 but that isn't going to say how an Mc engine is built.

 

[Lee H]

No idea Al. I think Mike Acres has a couple thousand saws and maybe more. Heard lots of
stories over the years. I myself have over 500.

 

[heimannm]

I think I have five of the 650/660 saws on hand now including one that Don sent home with me last June. 650 crankshaft in the front of the photo.



To the O.P., sorry about the derail...

Mark

 

[p61 western]

I think I have five of the 650/660 saws on hand now including one that Don sent home with me last June. 650 crankshaft in the front of the photo.

View attachment 175565

To the O.P., sorry about the derail...

Mark

Lol no worries. It's all great info Imo. Kind of nice learning about all the big Macs.

 

[Al Smith]

My main reason for rambling on like this is McCulloch is or was an American company .As such I would think they would design something ,such as this kart engine that would utilize existing parts like perhaps a screw on clutch from a chainsaw .I could understand Stihl not doing something like this because they use 10 zillion parts to do the same thing and almost none of them are interchangeable.That's typical German though .

 

[Bigmac]

My main reason for rambling on like this is McCulloch is or was an American company .As such I would think they would design something ,such as this kart engine that would utilize existing parts like perhaps a screw on clutch from a chainsaw .I could understand Stihl not doing something like this because they use 10 zillion parts to do the same thing and almost none of them are interchangeable.That's typical German though .

Al my understanding with the 101d motor is it was originally designed for ultra-light aircrafts, and the straight 3/4 shaft was to beef up the output shaft for that use, it wasn’t designed for kart use, it also had a decomp button and came with a recoil, the other kart motors didn’t seem to come that way.

 

[Bigmac]

The one in the pic has a straight crank, Not tapered. It is also threaded in the end so I
don't think it can be turned down and have any left for the threaded end like a tapered
crank.

I read somewhere(so I could easily be wrong) that terry can modify the 101d crank to work as a tapered crank for around $80, but again my info or the info I read could be wrong!

 

[p61 western]

I read somewhere(so I could easily be wrong) that terry can modify the 101d crank to work as a tapered crank for around $80, but again my info or the info I read could be wrong!

How often does the 101d show up?

 

[Bigmac]

How often does the 101d show up?

They are around, and the crank being different, Is less in demand because it is different, and because of that in usually great shape! Lol

 

[p61 western]

They are around, and the crank being different, Is less in demand because it is different, and because of that in usually great shape! Lol

How is the block compared to a 101b?

 

[Bigmac]

How is the block compared to a 101b?

They are almost identical, the side decomp is the only difference, and a flush exhaust port surface, instead of the recessed gasket surface for the 101b