HI everyone ,hope everyone is well ,and looking forward to a new year of vintage karting. I was given a Mcculloch 250 chain saw, and would love to make a kart motor and race it in the chain saw class.I have a couple questions. Where do I find a clutch extension for the stub crank? Also is it possible to run the clutch outboard ? And can I run my regular tapered shaft clutch? I did read Dave,s article on disassemble the Mac but not on what would work. THanks again everyone.
clutch extension for the stub crank = ebay used to have people selling them not sure if that's still true
clutch outboard = depending on clutch selection yes but i wouldn't - too much crank stress
can I run my regular tapered shaft clutch? no - 250's are usually stub shafts but if you luck onto a tapered crank you're in luck and it will work.
imho easiest solution is just buy the max torque clutch jim makes for the stub shaft mccullochs.
Max Torque makes a clutch that spins right on that stub. Works perfect. I made the first ones about 6 years ago so then Jim made them available so you don't have to jump through hoops to make it work. That's an 80cc saw so it can run in the Mac 49 class.