Ok

Here we go.

I have a 2004 400 ex. I bought it and it ran fine.

I took it out last week. I was feeling a loss of power or a sputter or some type of irregularity while in the high throttle range. If I am not mistaken it is in each gear or possibly only the higher gears I cannot fully recall. After noticing this issue about a half hour later she died. I could not get her started again.

I eventually loaded her up and took her home.

Got it home and it started up but I couldn't test the high throttle range since I was at home. So I rode it around the cul de sac and parked it.

Now here's where I went wrong. I have experience in small engines and can take them apart and work the carb and clean it up and get them running so I figured why not try on my new quad.

I took off the carb and took off every thing per the manual to find any blockages or worn items that may cause the issue but saw nothing of interest. So I cleaned it with carb cleaner and probably sprayed something that shouldn't have had cleaner on it but here we are and I don't see any rubber pieces that are now destroyed due to carb cleaner. The two jets I was able to remove I simply cleaned and replaced only one could possibly be put in wrong or to deep or whatever the f you call it but I eyeballed it pretty well. I know we need exact measurements but I figure let's try it should at least start. I continued to ray through some other air vents and such.

I took off the k&n air filter. It was dirty and don't have the kit yet but am going to just replace it anyway.

I am going to replace the spark plug ASAP

I am going to replace the oil and filter ASAP

I am going to check the muffler screen for blockage ASAP.

So I got the 2004 manual and followed most of the directions.

Now she's not starting and I'm betting it's not getting the gas yet. Is there a way to speed up the Venturi process on the carb or wtf did I mess up?



It's possible that symptom is not related to the carb but I doubt it

On the bright side at least I know The electronics are working


Any help is greatly appreciated

Thanks

I dive in why the hell not if someone else can fix it I can too!!!

 

Hmm, well the main jet would control your high RPM range fuel flow. Its not too uncommon for them to get gummed up and need to be cleaned. You shouldn't have damaged anything with carb cleaner. We usually drowned the things in it when cleaning them.

You should verify your getting fuel to the carb. Open the shut off valve and make sure it's getting fuel past the petcock. Also, make sure your overflow is open on the carb. If gas pours out of it your float needle is probably sticking.

 

Awesome i was thinkin gas int making it tothe carb yet or at least not yet. Ill start there thanks for releiving my worry on the carb cleaner i usually douse it all but was hesitant.

Thanks a ton

 

Not sure if these things have a CDI box or not but it could be that.

 

I am still learning a lot about these things myself so we are in the same boat here. I rode nothing but dirtbikes for 10 years before getting this quad, all new to me.

 

@rangerover the functions should be the same on a quad with a few so far so good on mine.

@koopa and everyone else

She's back running I just left it overnight and she seems to settle gas wise .

I rode it to a third gear and seemed ok and no leaks and no hot muffler atv the engine connection I think it's called the header. The real test will be out at the desert in ocotillo wells.

I will replace the other items soon . Thanks for the help

 

Does the ex have any mods? A hot header is a sign that you are running lean.

 

Is she jetted? If she is and you heard a lot of backfiring you may need to go up a notch. I was having the same problem this past weekend