Chainsaw Repair

My father had a couple 3.7 Craftsman but they were horizontal cylinder Ropers .The old man liked to tinker and he managed to put enough soup to them they would snap  crankshafts . The last one he ever did is now in Louisville Ky at my brothers .I'm thinkin the old boy must not have put quite as much go into that one .

He would buy those things for 40-50 bucks a piece with usually nothing wrong with them other that stale gas in the tank.I haven't checked but there probabley is a couple 5 gallon buckets full of parts obviously though minus the crank shafts or in a couple of unusable pieces of same . 

I think he might have just jacked the compression but never raised the exhaust therefore they never speeded up just pulled like a Georgia mule .The cranks could not take it .

It was a hoot ,we were always trying to out do each other .My brother in law got the bright idea to dope the fuel on a Mac 10-10 and he did .50 to one mix oil had just came out .So he mixes AV gas ,20 percent nitro and 50 to one and here he came .

My heavens did that thing boogey --for about a half hour then it came apart like a dollar watch .

Fact as I type what's left of that thing is in my shed .The piston looks like a bomb went off inside the cylinder .

Based entirely on the pix and P&C part# of your sears model and that it is NON AV like mine I would say a 2150"LE" 42cc. I have several 2150 and they are usually 36cc except the LE @42cc. I put the same 42cc jug and piston on my rebuild since they are the cheaper than the smaller one. All the rest of the parts are mostly the same. The 1975 is very similar and I have not researched enough to tell the difference from the 2150. 

The other thing that Poulan did that become confusing is they marked the side cover with a CC size when in reality they were actually bigger.   There was alot of saws that sold that way.   

I seen earlier WT's listed as 42cc and a little newer but still non strato ones listed at 40cc.   

I have a another early WT on the shelf right now. Like them the best of the WT's because of the throttle lock etc.


Also I had a red craftsman 42cc come in with bad topend and I just pulled the motor and slapped a 36cc listed one in it's place.  It's still out there cutting today.

I'm talking throttle lock on top of rear handle you push it in and it locks the saw at about half throttle.

I have no clue on the bore and strokes of them. I just keep sets together or replace with same known saw.  Like when I took a crank and piston out of a 260 and put in another 260 cylinder and case.