this aint right, quads cant touch me but a xr650r and yzf 426 (stock as far as i know) are woopin me I would like some expert advice on some engine mods i got fmf pipe, boysen super stock valves, 1 mm over piston w/sleeve, 91 gas with klotz oil (20:1)and octane boost. the xr says i am quick till 60mph then slower til 80 where i top out. I would like to get more top end power. my idea right now is to port a little to match the new liner to the cylinder casting, and maybe two base gaskets. The internals do look good after the rebuild, so i think its jetted good and mixture is ok. But i need more two stoke advice for what really needs to be done to beat these guys.