HELP! Oil Blown Out of Air Filter!

[Evan400ex]

Just got back home from the track. I have a problem and not sure what it could be. I had some engine work done a few months ago by T&T Racing. Mods are in the signature.
I was pushing the bike pretty hard today when it died on a straight. I could see my air box was full of oil. Almost every drop was blown out through the air filter. Does anyone know what this could be? I've never seen anything like this.:mad:

[plkmonster2]

The oil is from the crankcase. The crank pressure is released through there. I think that the most major thing that could have happened is that you blew an internal oil line. Other minor things could be a clogged pressure line, that built up presasure, and released it. Your carb is most likely full of oil too. I've had this happen on on of my Yammie trikes. Only happened once, and that was becuase the pressure hose got clogged, and then it broke loose, releasing the oil.

[Evan400ex]

Thanks for the help. I will give T&T a call and see what they can do.

my briggs & stratton pushmower did that today..

This can also happen if you've put too much oil in there..

[MIKE400EX]

Do a compression check.

Originally posted by Rico
This can also happen if you've put too much oil in there.. yep...thats exactly what happened now that I think about it :eek2:

[zephead400ex]

Originally posted by Rico
This can also happen if you've put too much oil in there..

That is exactly what happened to my buddy and his Pred. It was FULL of crankcase oil!!!!!!!

[ReconRider25]

can oil go out this line from doing wheelies? i think it did on the recon a little but will it on a 400?:confused:

[stupid driver]

i dont think it would from ridin wheelies, but i could be wrong. Isnt there a pcv valve in there to control the oil from escaping, unless it is from blow-by?

[Evan400ex]

We took it to the shop a few weeks ago and they are just now tearing it down. I know alot of you said the oil may have blown out of the air filter because there was too much oil in it but that is not the case. It doesn't have any compression and has a hole in the piston. I kept up with all the maintenance but was wondering how the piston could have gotten a hole in it? It was built in late February. It seems like I shouldn't of had any of those kind of problems so soon.:grr:

[KY Woods Rider]

Here's my guesses...

When you said that you were pushing it pretty hard and it died on a straight, I'm guessing that you were revving the living dog $#!t out of it. If so, you may have floated a valve, and then boom, you got a hole in the piston and a seriously damaged valve.

If that wasn't the cause, someone may have tried to lighten the piston by removing weight from underneath the dome and got a little carried away.

Originally posted by KY Woods Rider
Here's my guesses...

When you said that you were pushing it pretty hard and it died on a straight, I'm guessing that you were revving the living dog $#!t out of it. If so, you may have floated a valve, and then boom, you got a hole in the piston and a seriously damaged valve.

If that wasn't the cause, someone may have tried to lighten the piston by removing weight from underneath the dome and got a little carried away.

Couldn't a extremely lean condition cause a piston to practically melt or cause a hole in it??

[TRX450R2]

Does sound like over rev with that rev box on there? So ,what happened??? :(

[Striker49]

Originally posted by Rico
Couldn't a extremely lean condition cause a piston to practically melt or cause a hole in it??

Yes, that is very possible so dont count that out either. Speaking of which, I need to check my jetting...seems a little odd as of late.

[KY Woods Rider]

Originally posted by Rico
Couldn't a extremely lean condition cause a piston to practically melt or cause a hole in it??

It's possible, but surely to goodness he did a plug check after jetting it or at least he would have felt that it wasn't running correctly. But then again, I always have been bad about assuming that people are smarter than they really are:o

[Evan400ex]

I know it was jetted perfectly. So I definitley wasn't running lean. I was more on the rich side actually. It kinda ran weird after it was bored. It had alot more torque but didn't seem to be very quick. It felt like I had more snap when I had the stock bore. I don't know. I will find out more in a few days.

[Evan400ex]

I finally got my bike back last week. The rings blew off the last one and tore up the cylinder wall. 3 hours into riding it this weekend it did the same thing!!! All the oil went through the air filter and into the airbox.:mad: I don't know what to do. I guess I will have them rebuild it again and just sell it. I guess I will be going to Yamaha.

[tj but]

:devil: :devil: :devil: