Lots or air out the crank breather air box

[emerson137]

I have an 05 Rossiar Motor. Last race I noticed lots of oil in my air box? Checked my engine oil and it seames a tich low but nothing to what was all over my Bike. So I checked my tranny oil and it was way down.
What I dont understand is When I start my bike and put my finger over the breather in the air box, there is a huge amount of PSI there.
Motor still pulls hard Seames to have good Comp. Is there a seal inside that blew? Any help would be nice.
I plan to drop a little Die in the engine oil and see if its the engine oil or Tranny.
Oh I have a CP single ring piston.

Thanks guys

[scuzz]

I know this doesn't help you but...

I had something like that happen with my 400EX, it would blow oil out of the tranny breather. The funny thing was is that it ran great, had excellent compression and never smoked.

I ended up making an air/oil seperator and routing the ait out the top of it and putting an EGR valve in-line to proevnt moisture from comeing back in. I also made the oil route through the valve cover.

To this day I don't know what the cause was....

[jomama]

this is known as blow by. Its caused by when your air is pushed pashed your rings and into the crankcase. this means you need a rebuild.