Well i have had my motor kit from boygofast for 3 months now and at first i was having some real frustrating problems particurly with the clutch and especially the chain tensioner and I had to drill out the screws to the cover to put the chain on cause they were in way to tight and would not budge now i have a shorter chain tensioner and the clutch problem is solved and i even got a heavy duty back wheel and a gallon gas tank for the bike and ever since august the motor runs and fires like a champ and i have had no further problems it seems that i can only get a top speed of 25 mph but thats as fast as i care to go. and the frame seems to be holding up pretty good and vibration is not so bad. hopfully this will hold out for a long long time