04 Yz450 blowing oil out of vent

walent215 wrote:

Friends bike is blowing oil out of the vent . Worn rings allowing blow by? Could oil ring being overlapped cause this? Any ideas? Hes stumped...

Friends bike is blowing oil out of the vent . Worn rings allowing blow by? Could oil ring being overlapped cause this? Any ideas? Hes stumped at this pojnt. Thanks.

deccr250 wrote:

Are you talking about the vent pipe off the side of the cylinder?? If so...take the cover off powervalve on the front of the cylinder, the...

Are you talking about the vent pipe off the side of the cylinder??

If so...take the cover off powervalve on the front of the cylinder, the powervalve will be dirty and covered in oil etc.
Clean it up with carb/parts cleaner and try that. Happens all the time on the YZ’s and happened to mine. Cleaned the powervalve up and it sorted it.

walent215 wrote:

This is on his yz450f.

deccr250 wrote:

My bad....didn’t rest the title correctly haha