400ex problem

[04blasterkid]

(-)back fires on decel, no power, chop the gas and it stalls, hold it in neutral and it revs 1/2 the way and sputters/bogs

(+) starts easyly, dont smoke, and thats about it

im woundering what would causes this

story: always ran good no smoke/or poping, one day was doing slow wheelies for bout 10 mins, stalled it in a wheelie, let the front down started right up, from then on it didnt have no power, and wouldnt start after it cooled down, new plug fired right up, still no power.. likd i can hold it to the bar and dump the clutch standing on the grab bar and it wont wheelie.. on tar... so yea..

[zrpilot]

I gotta think plugged carb, like the main jet circuit. Time to take that carb off and check everything...

[04blasterkid]

i dont know much about it, its alot more stuff in it then a 2 stroke carb + i forgot to mention i broke a tiny chip off the plastic plate that goes around the jet, there was 2 like divits and one corner of one snapped off on me.. but i dont think thats the problem

[250rmike]

a 4 stroke carb is the same as a 2 stroke carb just may have some extra hoses going into it(havent worked with a carb in a while just fi) i would clean the jets make sure the float isnt stuck pull it and clean it out good while your in there. also does the clip that you broke hold the jet in and if it does is it moving around possibly letting the jet move around

[04blasterkid]

no its just a little peice of plastic that slides over the jet

my 250r carb, stock blaster carb, and my oko blaster carb... where simpler... i think 400ex might have TPS? idfk, but there is like a pluger and stuff off to one side:rolleyes:

[250rmike]

it should still come apart the same. just has a plug in it. cleaning a carb is cleaning a carb just like working on anything just take you time pulling it apart and remember how it goes back together.

[04blasterkid]

do u think this is the reason it has aboslutly no power?

[yfzfelix]

if you don't want to take the carb apart go to the auto parts store and get some marvel mystery oil and mix it with the gas and let it sit and run, my friends 4x4 quad sat all winter and they had a hard time getting it to start and when it did start they had to turn the idle way up for it to run, I told him about the marvel oil he tried it and it now runs fine, I think something was partly plugging the jet and the mmo dissolved it, now he runs the mmo mixed with the gas all the time and has had no more problems, might be worth a try

[04blasterkid]

nope, it was just the 2 screws that hold the throttle arm to the slid, so i put them in and its fixed, thanks for the help guys

[250rmike]

not a problem glad you got it fixed i never would have guessed something like that

[04blasterkid]

me eithe runtill i went to clean the carb and found 2 loose screws just rattling around haah