Recent content by David Hearn

Thanks for the advice on pistons, boring out cylinder, and jetting, I really appreciate it! Dave

Hi, I am replacing a 66mm piston on a bone stock (stock exhaust, Mikuni carb, porting,etc) machine with a piston that has the bevel on the front side that changes the exhaust porting. Someone said I need to change the main jet to match. I operate machine at 100 ft. altitude. Can you give...