HELP NEEDED - CRF450 Pumping Oil Out Valve Cover Breather

R

rikhek

Member

Nov 3, 2004

67

0

• Nov 22, 2009

• #1

My 05 Honda CRF450 is putting a significant amount of oil out the valve cover breather. NOT a "normal" amount. Bad enough that it goes below sightglass after 2 hours run time. I'm certain it's coming out the vent. Bike runs fine.

Would appreciate someone letting me know what's wrong.

TIA

Rick

 

Last edited: Nov 22, 2009

M

Matt90GT

Member

May 3, 2002

1,517

1

• Nov 22, 2009

• #2

Most likely blowby of the piston.

Time to do a leak down test of the motor.

 

S

Spokes574

Member

Apr 27, 2001

171

0

• Dec 19, 2009

• #3

to me that is one of two issues:
-Worn piston rings will do that! - this was in last month magazine Mx Action
-Over filling the oil, putting in too much oil
Spokes574

 

R

rikhek

Member

Nov 3, 2004

67

0

• Dec 29, 2009

• Thread starter
• #4

To those interested the top end was worn causing excessive blowby. New top end and all is well.

Rick