Got a Good pipe? Good compression on 2nd 650 150 psi good main bearings and seals.... allrightyy thenn? Pipe, and jet carb per exhaust manufacture. Will give a nice upgrade then maybe upgrade prop, MSD enhancer or A head replacement with 30cc domes will boost you to 180-185 psi on stock motor no higher if you wish to stay on pump gas. Racing reed set but if the factory are still tight you dont get that much gain. Then if you still have money left a lightened flywheel gives more snap from idle !!! Some people even go so far and remove the foam from the sides and nose as when it gets saturated with water it does weigh a lot and removing weight is good! Or just leave it stock and have fun with it !!!! Until you just need more power, more speed, or just MORE or you'll soil yourself !!! That was me this past month Just did this but the MSD and the fly wheel and the MSD is on order... And it does work. Money = speed/power! But it never fails when after you do all this work and spend all that money someone will come with another sled and smoke you.......Just please youself and you wont be disappointed! Good luck! as I got smoked today by a modded out 701 and my modded out 650 couldn't compare. Oh well i still got wet....