rearenginekarts.com

Hello. Newbie here. I took on a project to help a friend’s kid with a vintage kart. It has a McCulloch 101b engine. Unfortunately the clutch assembly is missing. It has a tapered crank end, no key slot, reverse threads. I am trying to find a new old stock or used clutch, but the ones I have found are part number 60315 and have a key slot. Not sure if they will work. Looks like the kart was set up with the chain sprocket outside the clutch hub. Any advice would be greatly appreciated. Thank you. Mike

The left hand thread cranks typically use a left hand threaded clutch hub so no keyway is necessary & it makes the crank stronger.
It's possible to use a LH nut but with no keyway I would not recommend it.

What kind of kart / mount setup do you have?

Hey, Mike. If you want a dry clutch for Vintage, Max Torque makes a terrific one. You have to tell Jim Donovan whether you want an outboard or an inboard sprocket. Some engines sit so close to the kart that an outboard sprocket is necessary. You can find an oil filled clutch, but the learning curve is greater. the dry Max Torque is strong and fast, but it ain't cheap. Call Jim Donovan at (630)369-9600 and discuss the application with him. Horstman also made dry Rev Grip clutches, but you'd have to find a good used one of those. Horstman, Hartman, Hegar and others made oil-filled clutches for the 101B. The dry clutch is easier to get used to things with.
I hope the kid you are discussing is old and proficient enough to handle a 101. They're pretty strong engines. Ted J.

The 60315 clutch has heavy shoes and a low engagement speed for chainsaws.