The clutch is a standard 76mm or 78mm, whatever, I don't remember the exact. But it is a standard 2 shoe centrifugal clutch. There are many, many vendors that sell them. eBay is covered with them. You can probably buy them at local lawn and garden equipment stores, Northern Tool or where ever. There's nothing sacred about the clutches. Standard stuff. They're cheap, like $2.50 at Harbor Freight with maybe 4 or 5 dollars shipping, but they're shipping takes about 6-8 weeks. Andy in the previous reply is right about a powerful engine. At least they are for something as small as they are. My total weight, myself and bike combined is about 280-300 ppounds. no problem even pulling moderate hills. My Harbor Freight 50cc will outperform my Honda GX35 in all aspects. Go figure !