oil resovior full of gas

[kamsdad97]

I went riding with some friends, it was on some trails and a motorcross track. the oil level was fine before i left. when i was riding the 400ex started acting up, it wouldnt rev up without sputtering. i looked at the air filter and it was pretty dirty. i rode back to the truck and when i checked the oil it was full of gas. is this from the air filter being dirty? i think the bike was flooding out? any help will be appreciated. thanks

[kamsdad97]

has anyone ever heard of thiis happening? i tried to do a search but found nothing.

[250rtone]

I could happen, but i have never heard of it.

[Quadzilla]

Only thing I can think of is that the gas is blowing by the rings (bad rings) causing the gas to mix with the oil. Anyone else wanna take a stab at this one?

[wheeltrax]

i was thinking the bad rings also.. but im not 100 positive..

[SGA]

Hmm, thats a new one on me. Very rich with bad rings I would guess. For rings to be that bad, it would be puffing blue smoke like a mofo. Clean the air filter, change the oil, check your jetting, let er rip.
Also check the gas tank cap, make sure its not building up pressure. (clogged vent hose or cap)

[Quadzilla]

The float on the carb may have gotten stuck for a bit and caused excess fuel to go down into the cylinder which may have seeped past the rings (even if they are good) and flooded the crankcase with fuel. Change the oil and see if it happens again. I would also check the carb's floatbowl to see if the float is moving up and down freely...

[SGA]

I agree with you. Thats why I mentioned the gas cap building up pressure and pushing gas pass the carb needle seat. I forgot to mention about the float sticking also. Good catch.

[kamsdad97]

thanks for the help. its not blowing any smoke, and has plenty of power. before i bought this bike i heard of someone else with this problem but he hadn't found a cure yet.

[amosclifford]

i dont remember but dont the carb vetns and crankcase vents run into each other on the 400ex? Dirty ait filter and crnakcase trying to suck air since not getting air easily sucks fuel drom the vents of carb ?????

[kamsdad97]

I changed the oil and filter, and cleaned out the carb. cleaned the air filter. everything seemed to work fine. I rode it around for about an hour and no problems.

[SGA]

Sounds good:)