My New Project (MC-54-250) - not the "B" Variant

[Ebuddy]

Hey guys!
Well, while my 150cc is still a project, I went out and bought a 2008 Roketa (Jonway) MC-54-250 (CF Moto clone). It runs like a top and can carry my fat rear end up to (so far) 64.3mph (GPS verified).

My perplexing issue is that the bike has stripped 2 variator covers (the part with the fan louvers) at the drive shaft. The teeth on the drive shaft don’t seem to be worn but the cover (I actually purchased an entire assembly) went from brand new to completely smooth in about 350 miles. When I replaced the variator assembly, I also replaced the entire clutch assembly with new units from ScrappyDog.

The belt seems large at a 918/22.5, but seems to be correct given that the bike has 13” wheels.

Any thoughts of why this might be happening?