i do not know everything that is done too this motor im waiting for a email from the previous owner to tell me whats all done too it. he raced the 200 4-stroke class (he moved up too the 450 class) in belliville illinois and semo raceway in sikeston missouri. this bike has won pretty much everything in the 200 4stroke class for the past 2 years according too semo's website. but what i do know is it has a nickle clyinder sleeve, .80 weisco piston, some major porting, uni filter, 38mm keihin pj carb, vitos fat bastard head pipe and silencer. other things it has done too it besides the motor is its got the front and rear lowering kit +4 durable wheel spacer plates in the rear and +3 stud spacers up front, hydrolic rear brakes, and full works shocks, paul turner handlebars.. along with alot of other small things. it is bad fast for a blaster. its hard too keep the front wheels on the ground it seems that that is all it wants too do lol.