Oil Tank Breather Help

Hi Guys.

I'm new to this but i know you guys will keep me right.

Just bought an 02 YZ250F. has 03 cam conversion, and a wet sump conversion, my problem is the oil tank breather it is attached to the cam cover but the other end that was on the oil tank is loose and it blows oil out.

Can i block the end to stop loosing oil?

if i attach it back to the oil tank will it blow oil out of the sump back to the frame?

or is there something else missing from this conversion to stop the oil escaping?

Thanks in advance.


You can not block the end. It is there to help with the backpressure in the top of the motor.

If you have more than a couple of drops of oil coming out of the hose you have bigger issues. First check to make sure you are not running to much oil

Oil capacity:

Periodic oil change 1.5 L (1.32 Imp qt, 1.59 US qt)

With oil filter replacement 1.6 L (1.41 Imp qt, 1.69 US qt)

well put it back on the oil tank and dont let it flop around in the open!

sounds like it is time for some new piston and rings!

He has a wet sump conversion. If he's putting in 1.5 L of oil it sounds like it's overfilled.

Thanks for the advice,

Did an oil and filter change and it was over filled.

Very poor maintainance as the bike came from a dealer. will test it at the weekend hopefully sorted now. :p

Thanks once again.


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