caterbrother150
Well-Known Member
i have a gy6 150cc and i order a big bore kit to 63mm and i went to put the cylinder on and the back on wont go into the engine casing like it should. the the back of the cylinder is to big. when i talked to the guy i order it from he said it will work on all 150cc gy6 engine. what do i do to fix the problem????