help, oil in airfilter box. stumped???

[hotlicks]

2001 with a 440 kit. Have checked oil level repeatedly the correct way and am 100% sure there is not too much oil in the engine and the filter is in correctly. I have even lowered it to the hafway mark on the dipstick. When you begin to ride hard oil fills up the overflow tank and goes into the airfilter boot, thus sucking it into the carb and it begins to smoke and bog etc.. What could be the problem. Thanks

[GPracer2500]

If you're sure there's not too much oil in it than piston ring blow-by would be my next guess.

[hotlicks]

It is not piston blow by because it is coming out of the engine crankcase overflow tube and going into the overflow reservoir. The piston and rings and cylinder are in tip top shape.

[Barrymaxx]

SOunds like blowby to me.

When compression gets passed the rings, it creats presure in the crank case. Whick is then vented out the tube that connects to your boot. The crankcase is full of oil, that mixes with the escaping air, and wa laa, you have oil in your airbox.

Cant think of whatelse it would be

[Rip_Tear]

take the side cases off, check your filter screen under the pump the clutch side, check out the left side too, there could be something odd happening over there to cause the over flow through the tube.

[hotlicks]

Is there any way to check to see if it is blow by ( leak down test, compression test etc. ) ?

[Rip_Tear]

A compression test might help to see if you have blow by, if you know what the compression should be. But if you know it's coming though the tube into the air boot, then that's the problem.

With the left side, I'm just thinking that something odd may have happened there, creating some way for the oil to be getting too out that breather tube.

[RiderTRX400ex]

even though you say piston and rings are in top shape, i bet its still blow-by. it happened to me.. i even re a piston and 10 hours on it just to still have oil in my airbox.. it ended up to be uneven sleeve to cylinder contact.. compression leaked into crankcase.. created pressure.. and DUMPED oil into my airbox

take off your cylinder and check the sleeve for patches of discoloration "hot spots"

GL

[gcart2]

change your rings. if u donmt 1 day u will ride hard and end up blowing topend. buy a few extra sets of rings. the burn rings fast. i no u think they r new but they might be worn. if that doesnt work its your piston =(

[Barrymaxx]

What I would do on a car is pressurize the cylinder. Then listen in the exhaust and intake. If you hear air hissing, then you would know that that valve is leaking. Also works for testiong head gaskets.

Take a hose from a compression tester and screw it in the plug hole. Then hook it to compressed air(not too much pressure, like 60-80 psi will do)

Now pull the breather tube off and listen to it. You will probly hear air hissing. If you can actually feel air coming from the tube, then you deffinitly have some serious blowby.

[Sparky_20]

or for now run that hose beneath the bike and plug off your airbox :devil:

[RiderTRX400ex]

im tellin ya its the sleeve :rolleyes: