- Aug 30, 2017
So I've had this same engine for a year, my first engine and its going good. High comp head, porting, expansion chamber, porting (haven't matched the transfers on the case yet) and with a 44 tooth sprocket it does over 40mph at 10000+ RPM. It seems that I got a very nice crankshaft from the factory with very little wobble, but my bike vibrates like hell, and I mean the kind of hell where your feet go numb after 30 seconds of riding at high RPM. I have a cutout in the piston skirt so the intake port is fully open at TDC and I drilled a small hole with a channel going down to the wrist pin. I've seen people say things about balancing crankshaft and pistons and drilled into the crank, so what is this all about? Is there a forum going into detail on this? Please let me know anything you guys know, thanks, -Matt.