all u got to do is rebore it dude, trust me i have the vitos 240 and it sh*t the bed on me due to the sleeve dropping out of the casting a little, i dont think they are pos's it ran like a friggin raped ape when i had it running, plug was good, it was the company when they put it in the casting they didnt do enough of the heat up cool down cycles so when it heated up it dropped the sleeve a small amount. now i could never figure out why i was having problems it was jetted right and everything was good but i wanted more out of it anyways,took it off and found some scarring, not too bad, hone fixed it, i also had it ported and fixed by ken oconnor, sleeve drop was the root of all my problems. also dont use the gaskets vitos provides either they are so sh*tty, i went through 2 sets of base gaskets and finally ordered cometic. i promise u with the right jetting and a bigger carb for it u wont be disappointed. u constantly have to maintain it, do a leakdown test with a tester or spray some starter fluid around all the spots it is prone to leaking, base, head, reeds etc. when ur jetting do plug chops, only way u will know ur spot on the jetting where it should be and run 32:1, some people run 50:1 depends what u want to run.