Kx 500 performance problem

[paulc1978]

Hi  I have a 1990 Kx 500 wich i bought as a non runner i've rebuilt the engine had the barrel relined to standard size i've set the ignition timing and set the carburettor jetting to standard Main jet 168, Slow/pilot jet 60, needle N28M, needle clip position 3, air screw 1 1/2 turns out.I live in the UK 70 metres above sea level average humidity 60% But the performance out of it it is nothing like it should be, it is really flat lacking power nothing like the arm wrenching beast they are.I had starting problems at first with it flooding all the time i adjusted the float level with a float level gauge and this fixed the problem. The only time it has ran o.k is when i rode off accidently with the fuel off it took off like a rocket just before the fuel in the float bowl ran out, could it be a jetting problem. Any help would be apreciated. Thanks Paul

[KXcam22]

Paul,
  I would double check your power valve linkage. It sounds like it may not be working.  Your jetting should be fine for now at near sea level, a touch rich but fine until you get it broke in and can do some fine tuning. Cam.

[KX500freak]

like Cam mentions..
check valve ,take the cap off ,check for movement while revving up
i had the rod disconnected once ,it was like a xr80 so slow
hooked it up  right there and then ..it flew..

as for jetting


how s she smoking ,
excessive ?

you need to double check carb too
gasflow from tank to carb is correct ?
float needle still good ?

succes

[fluffy]

if it runs fine with the fuel off.what does that tell you? sounds like everything is good except for fuel. sounds like you should turn fuel on for a bit turn off and set bike up level and take fuel bowl off. when i did mine as soon as i broke screws free fuel came out. stuck needle always flooding. i think its flooding. start with the easy things first. good luck.

[KX500freak]

it seems TS is still workin on it ??

paulc1978 ,you,ve red the advices given ,come in please