my 400 cuts out when it idles, it goes away when i ride it really hard for a while, but when i let it idle again it goes for a bit then cuts, this also happens when i let the throttle go and coast.

 

whens the last time ya had your valves adjusted??

 

Did you re jet when you put the filter on? You are probably running lean on the pilot jet.

 

everything was jet properly, if you guys have been reading some of my other problems you would have seen that i also spit blue smoke when i let off the throttle. i think my 400ex is a lemon, because i was racing a car down my road when i suddenly stopped. the lights quit so i think i have to replace my wiring harness too. which i replaced just 1 year and a half ago. and my spark plug somehow loosens itself out by itself, i have had it blow out on me when i was on the trail before[img]i/expressions/face-icon-small-confused.gif[/img] im only 16 so i dont got alot of money to fix these things so its parked for a while. and dont anyone tell me to buy a yamaha, thats not even an option lol

 

did you get the extended warrenty?? if not get a new piston and valve seals. that will solve the smoking and mabe the cutting out b/c if the piston is not getting the right compression/ or wore out it will do that try that and see should solve the problem. about the spark plud i have no idea does it titen up all the way then you put it back in? as far as the wirring harness try a battery first then chech all of the connections the ground wire that hooks to the frame take it off and sand it down and also sane the frame down where it hooks on.


hope this helps

 

mt battery is brand new, and i did tighten the plug in all the way
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