CRF250 covered in oil.

Here's the story. The crank on my 2010 need to be replace so we pulled the motor and put in a new crank all new bearings and all new seals and gaskets. We put the motor back into the frame and had everything bolted up when I realized the shifter was not shifting anything. We pulled the motor again and split the cases. The shifting mech had come apart when we were putting in the new crank. We fixed the mech and put the cases back together using the same gaskets. I took the bike for a ride today and when I came back in I realized the engine was covered in oil. I REALLY do not want to pull the engine and split the cases for the third time this month. But it is probly leaking because we used the same gaskets right?

I believe you answered your question right there. It's possible the oil is getting pushed out of a vent hose but unlikely. Gaskets can tear or get bent after use. I hope you didn't re-use the base and head gaskets too because that can cause more trouble. If you want confirmation that you need to replace the gaskets I'll give it to you. "Replace the gaskets".

Gaskets also squish/distort after use, for a center gasket I would never reuse it, too much of a pain to replace as you are aware of.

I have reused the center gasket before after making a mistake and it worked out okay.  I use a light coat of yamabond on every gasket.  Probably overkill.  Just as a thought if the oil is coming from up top, make sure you have the right seals on your valve cover--I am talking about the seals that hold the valve cover to the head (2).  I had the wrong seals once and oil was streaming down he left side of my head/cylinder/case.


Good luck. The thought of splitting the case again must be frustrating.



One time I didnt torque the head cover down enough and it was leaking oil everywhere, I thought it was something real bad at first. I would be sure of where it was coming from before I split the cases a third time.

Found the problem and I feel real stupid now. I went back re torgue all the engine bolts and realized the bolt you take out to get at the cam chain tensioner wasn't there. Put that back and no longer any oil leaks.

Good find.  There are a lot of bolts on theses engines and if you're like me you were working on this between midnight and 3am.

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