Scott -- I am also thinking you have a 5/8" crankshaft and not a 1/2" but YOU have to verify that for sure. Lets figure out if the china clutch is your problem. Take it apart and look at the spring. If it stays in a circular shape it is been anneal and is now worthless. That is the heart of the clutch--the spring. If it stays straight as an arrow then there is NOTHING wrong with it but if it stays arced then it has been annealed and is useless. Music wire can only take 250 degrees F while stainless steel can take 550 degrees F. We only use stainless because run away go karts are lawyers delight. The next thing you want to find out on the engine is at what rpm does it idle so then you have the correct spring in the clutch. Historically old Briggs engine idled at 1,500 to 1,600 but in 1999 they quit selling engines to the kart manufacturers and they started using Tecumseh which idled at 2,000 so now ALL clutches made by us, Comet and Noram were coming in at 2,200 to 2,300. Honda still idle low around 1,200 so you were wasting a 1,000 rpm before anything happen on the clutch if it was mounted on a Honda but since Honda was so expensive no one used them on fun karts just the rental karts had them and most of them had a built-in-wet clutch.
How often and when do you lube the bushing in the clutch? How are you lubing it?
