[jerickson]

After my last race I saw some oil had come out of the hole in the side of the cylinder head. It wasn't a lot of oil; just enough to leave a stain going down to the clutch cover. Any ideas on what it could be?

I checked the spark plug and it was tight. The tube that the spark plug goes in is still pressed into the head. Bike ran fine all race. No oil in the water or puffing smoke. Valve cover appears ok and it was tight and sealed to head.

Does that metal tube that the spark plug sits in come out of the head? And is there a seal at the bottom? Only other thing I could think of. Thanks

[hall_philip]

sounds like the seal that's on top of the tube and mates with the valve cover. I would just replace it to see. the tube is permanent and does not come out but the seal is the only possibility as I can see.

[JimDirt]

hall is correct !

The hole in the side of the head is a water drain for the spark plug area , there should be no oil in it , if your getting oil , then it has to be coming from the valve cover SEAL that is for the Spark Plug Tube , on the inside of the valve cover there should be a seal where the spark plug tube goes into , that would be where the leak is ,allowing oil to weep into the drain tube and run down the head

Part # 1

http://partsfinder.onlinemicrofiche.com ... HEAD-COVER

[jerickson]

Thanks! I will get a new seal.

[JimDirt]

Sometimes when re-installing the valve cover its possible to screw up the seal by forcing the tube into it , after that , it will usually leak

Look very carefully at the lip of the seal for damage , it may be very slight , but any damage will allow it to leak with all the oil splattering around inside the cover when the engine is running , as well as look inside the tube and see if there is oil in the tube , that will be your sign that the seal is bad , (don't forget to clean the oil out of the tube) there is no other place that the oil could come from to get in the drain tube

When installing the cover , gently rock it back and forth when you get to the tube and you will feel the tube slip into the seal

Also check the edge of the tube for damage , if its marred it will tear the new seal , so if its got any burrs , use some fine sandpaper to get it back to smooth before installing