i have been looking at the kits,measuring my bike for a ring belt drive but still looking at 4 stroke ,two stroke,motor sizes can't make the decision no which one would work best,can anyone give me some help.I weight 228, want to trail ride maybe on the road a little! have a china mountain bike had to stop riding my old knees started giving me trouble, i rode almost everyday for a long time! any help on this would be appreciated.From East Texas! Thanks