07 YZ450F Blowing oil out valve cover breather tube

[crj900pilot]

My YZ540F started blowing oil out the valve cover breather tube so I had the cylinder honed and put in a new piston and rings and valve seals thinking blow by. Now its blowing out even more. I had a puddle after 16 sec of running. Any ideas???  Thanks

[grayracer513]

Oil overfilled?

[crj900pilot]

Its def not over filled. Anyone ever heard of a cavtating oil pump doing this?

[drtrcr400]

As long as the oil isn't over filled you still have blow by. No two ways about it.

Edited January 19, 2016 by drtrcr400

[grayracer513]

Its def not over filled. Anyone ever heard of a cavtating oil pump doing this?

 

Not cavitating, no.

 

Check this: If the dip stick is loosened or removed, will oil come from the dip stick hole?