Carb Problems

[bendrewjris]

I installed a K&N with a dyna jet kit on my 01, 400EX. Bike spits and sputters above 1/2 throttle. I've checked all twice. Any and all suggestions welcome.:confused:

[ridesa02400EX]

maybe jetting??? same thing is goin on with mine everyone says its jetting i just havent had the chance to get it rejetted yet

post a list of your mods and a better description of what and when its happening.

Sounds like you may be taking the carb off again.

[bendrewjris]

no other mods

Try running it with the air box lid off and if its better then I would say you went too high on the jet kit and are running rich. Note it may not run right depending on how much extra fuel you are pumping in there.

Most machines are jetted rich at the factory and you could most likely run the filter with the stock jetting.

Not everyone will agree with me but way too many quads are running very rich and that robs power worse than the stock silencer.

[Maryland 400EX]

Sounds like like you're too rich on either the needle or the main jet. Have you checked your plug? It will determine if you're experiencing a lean or rich condition.

[ridesa02400EX]

if the sparkplug is black is that to rich or to lean?

[frogburner]

If you hold the throttle to about 1/2 throttle,, will it load up until punched wide open??? Or does it crackle and pop real bad when you let off the gas in high gear??? I ran my dyno jet at the 3rd notch, with 170 main, with no airbox lid