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Like Greg said it could be the one way bearing. You can try removint it entirely and see if it still acts the same. It's also possible its the wrong wet clutch. I've seen quite a few for sale from various manufacturers and I've read reports of ones that didn't fit correctly or dont work properly because the size is slightly off. Unfortunately that's an issue with Hisun making slight changes between a bunch of models that use essentially the same parts.

Alien, I think that is some of the cause of wet clutch issues reported on these units. Lots of people refuse to read a manual or understand what they're working with. It doesn't help that Hisun (and their branded distributors) give different oil specs in different literature. Once the wet clutch wear starts, it progresses quickly. The worn off friction material in the oil i'm sure doesn't help lubricating other components either, which could be part of the common wear ("stretching") issues with timing chains too. If you do need to replace a wet clutch a full oil/filter change is required too to get that crap out of the crankcase.

Bolt M9x109, for instance this head bolt is available at Motorcycle Doctor.

Did you take a look at the parts diagram?...https://alpha-sports.com/massimo_parts.htm?q=massimo-parts I suppose there may be a unique situation that only a 1 off bolt or screw may work, but everything I see on the parts diagrams are standard metric bolts. They are after all trying to minimize costs, and creating unique hardware hardly seems productive.