JimB

2004 Honda 400ex Misfire

7 posts in this topic

Hi Im new to the site , I have a 2004 Honde 400ex it starts and runs strong down the road but when idleing it acts like it is misfireing or un burned gas is building up and the fireing.

I have taken the carb apart clean all ports new dyno jet, jet kit with a 170 and no air box lid just like the instructions clean k&n with outerwears new spark plug , fresh 100 octane fuel. Any and all sugestions would be appreciated.

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sounds to me like your low speed idle jet is clogged if it was sitting for a while boil some water with lemon juice and put your jets in it for like 5 to 10 minutes should open them up

Louk

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Welcome to QUADCRAZY!

* Added year and make to your thread title as per guidelines.

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I have tried everything, today i remove the decompression and with no avail , it still has this miss almost like it wants to die for a few rpm and then back to life for a few and then again back and forth , but when you run it down the road the quad runs like nothing wrong at all

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anybody have any input to maybe a cdi, or the coil being the problem.

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Valves out of adjustment maybe, your idle could just be set too low, could be a small air leak in the intake somewhere causing it to run lean at an idle.

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