250 ex problem please help!!!

[SGARCIA89LX]

I have an 03 250 Ex and everytime we ride when i go through a rythme section fast my quad starts acting up.it starts stalling and misfiring and sounds like it's not getting any gas.then after awhile of trying to get it to go it clears out to normal again,but if go through the up and down section very fast it'll do it again.also gets alot of oil in the air box.looks like is coming from the crank case breather hose.any ideas??

[Honda10]

This is the exact same situation I had, the quad is not getting enough fuel compared to the air mixture. What I did as a temporary fix was pull the choke up a little bit and tie something around so it stays there. But the problem is probobaly there is dirt or something in your gas tank by down at the bottom by the filter. So you will probably have to take it off and clean it out.

[RideRed84]

Wouldn't hurt to clean the carb too

[SGARCIA89LX]

i've cleaned the tank and the carb twice already and installed a UNI filter and it still does it and when i cleaned it the second time they were both spotless .also whats up with oil coming out of the engine breather tube?

[Honda10]

Well did you rejet it after you put in your uni? That could definetly be it. I have heard the 250exs come a bit lean from the factory, so bump your main jet up to a 98 and that will solve the problem.

[SGARCIA89LX]

but wouldnt it affect it even on a long stretch of road at full throttle if it were the jetting?it only acts up when is going through a rythme section in the trails we ride in.I dont know i'm just trying to figure this out. i let it idle and try and rev it for about 10 min and it starts clearing up.:confused:

[Honda10]

that was the same problem I had so i just pulled the choke out a little bit till i can find the problem.

[SGARCIA89LX]

I TRIED PULLING THE CHOKE BUT THAT DIDNT WORK IT STILL DID THE SAME THING IT ONLY GOT WORST.I'M GOING TO TAKE IT APART AGAIN AND CLEAN THE CARB AGAIN AND REJET THE CARB.IT'S WORTH THE TRY.

[ryanh250ex]

The excess oil thing makes me worry. are you getting alot of tailpipe smoke?

check your fuel lines, and also make sure there isn't anything in the gas tank (dirt, sediment, etc). I'd also check your plug, you might be getting some excess blow by.

I once had a similiar issue. I was running it through the gears, and it felt like it slowly started getting leaner until it backfired while i was on the gas. I had to limp it back home, bucking and misfiring the entire way. It wouldnt start for a good 10 mins, and then it did start, it ran fine?!?! To this day I still dont know what it was, I'm guessing there was a small piece of dirt or sediment in the tank that finally passed through.

[250excrf250r]

there is dirt or gunk in fuel line and when you go fast it jumps around and wont get gass. this happened to a friend with 02 250 and it also could be airfilter but the i am positive there is dirt in carb, air box ,fuel line. i would take apart, clean, jet

[250excrf250r]

i would also Drain the FLOAT BOWL in carb