Cylinder head weep hole.

Just rebuilt the motor in my 04 CRF 250..when running there is oil comming from the weep? hole thats in the right side of the cylinder head underneath the rocker arm shaft bolt hole.

What could cause oil to come from here? the motor seems to be getting very hot very quick, so im thinking that the oil pump is not timed correctly with the crankshaft. maybe one tooth off?

anyone got any suggestions?

First, check your spark plug. It may not be seated all the way. That weep hole is a drainage hole for the plug well.

Humm interesting, I will definatly check the torque on spark plug...


spark plug is torqued, still have oil comming from weep hole.

could it be oil blowing past the rings? But if it was oil from the bottom end, going past the rings it would just be burned and not flowing out of the weep hole right? Because there is no smoke from the exhaust leading to believe that oil is being burned...


Did you check the rubber seal on the center of the valve cover? This is where the cover seals against the top of the plug well. Possibly pinched, torn, or gone all together....Maybe, while running, oil is leaking out if that circular seal, around the top of the plug well, and out the drain hole.

I can't think of any other reason you would have oil coming out of that



Just thought about that...goin to check it now. thanks for the picture!

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now