by abmjl » Wed Apr 14, 2010 5:11 am
hi , i have an 05 450x that i used when i first started motarding n loved it. did carb mods + fitted r header pipe n fmf muffler. it had good torque out the corners but lacked alittle pull at topend.
got tired of changing setup from motard to dirt so got a 04 450r for motarding n x for dirt.
i have done the usual carb, airbox n pipe mods
ive removed the base gasket to lift the compression, a cheap and effective way of giving you alot now torque, but you need to fit a carb jet, did remember what size, in the oil line to restrick the flow to the head. look at your bass gasket.
fitted a stage 3 hot cam n some head work match porting inlet rubber n exurst copper ring n debering n rounding sharper edges in ports to increase flow.
i have done these mods at seperate times so im able to notice the differnce it has made each time.
i have to admit i thought i would get more top end pull out of the stage 3 cam but was alittle disapointed.
fitted a jd 2 stage ignition n that made a big differance, igintion cerve is very importent.
so ive got good power all though, lots of punch low, mid n it keeps pulling all the way though till around 11500 rpm. i have onboard computer so this is accurate.
admitedly ill need to maintane it more often with those revs.
so as far as your x goes id tend to do the carb, airbox, r pipe n aftermarket muffler 1st then go for an ignition n lift compression alittle n maybe stage 2 hotcam, which ive been told is very semiler to the r cam. i dont think the stage 3 would do the x justise cuz of heavy flywheel n head design n i think piston skirts are alittle longer to.
and about ss valves, yep more relible but also more wight so less power. i havnt had a problem with my x, ive never touch it. i bought it at 22hrs n take the valve cover off for the 1st time at 120 hrs n they were spot on. i ride it hard too, so it gets a thashing. its done 160 hrs now n still screams. i put it down to using fully sinthetic race oil "fuch 15/40" n changing it regarly.
big bore kits n strokers for motarding, ive talk to lots of different people bout them n the general thought was they done like the revs n thats what you want for motards, revs. guys ive raced with have put then in then taken them out again. my r before the engine mods on a 1/8 mile straight easierly keeped up with a ktm 560, not standard gearing of course.
just some thoughts from my own experance with the 2 bikes. hope this has helped.
jason.