were fresh into this moter bike gig , my son and i each built a bike he drives his back and forth 35 miles a day to work ,, lasted until it was broke in then he scared a piston lost power ect. so we got a new head and piston , but while we were waitin i told him that back in the day when i was young we would run 2 stroke Go-carts in the 60s and early 70s and we would port and polish them and get a lot more power out of them so away he went polishin up everything the whole inside of the case the back of the new piston then we found why they burned up the casting slag wasnt removed in these engines so sooner or later this brecks lose and gets sucked into the chamber ruins your moter so i wasnt to happy with the quailty of these chinese junk moters,, but i gotta say after spending 80 bucks for amercan bearings for the crank polishin everything up polish intake and exhaust ports and manifolds he sparked it up last nite and oh my god what a diff. no noise ran smooth power up the yegyang what a diff a little TLC makes after seeing this i recamend before you put your new moter in do an american rebuild, you wont be sorry things like all the gaskets are to big blockin the passage of the gas mix all these little mistakes the chinese dont deal with need to be delt with if you want a good running motor Poul and Tyler
