400ex missfire

[latravcha]

My 400ex is missfire or spuddering in the higher rpm range. I adjusted the valves and this did not help. does anyone have any suggestions to fix this problem.

[ommkevin]

check the carb and the part on the carb that controls the higher rpms

i forget what its called

[2004exrider]

check your main jet, could be to lean or too rich (the jet might have fallen out to). only way to know is to look at your plug. get it up to operating temperature and then ride it at 3/4 throttle and up for a few seconds. after that look at the color on it. white- lean, black- to rich, grey-golden brown- perfect.

Jimmy

[ride_red666]

if its misfiring check your spark plug. it did the same thing in my truck and it was the spark plugs.