So my exhaust valve cover is leaking a little oil on the bottom right side (when viewing from the front of the bike).  I tried taking it off, wiping both surfaces completely down, and flipping the cover.  I torqued the bolts down pretty hard, but Im still getting some leaking.

The gasket looks fine.  Anything I can do to fix this?

Remove cover.

Remove "O" ring from cover.

Flat-sand mating face of cover on 180 grit sandpaper until entire surface shows consistent hit marks from the sandpaper.

Check head machined surface for any wrench dings (they happen).  Usd a fine flat bastard file to fix any issues you find.  (bastard style file cuts flat and fine, it has no cross cut marks to it)

Put it all back together with a new "O" ring.

Torque to factory recommended spec only.

OR .....

flatten the cover and head as above, reuse old "O" ring and see if you get lucky.

Several things can lead to a leak.  A warped cover, a cracked cover, an o-ring that has become stiff with age, scratched on the surfaces, either on the head or the cover.

Try this: Take cover off.  Clean surfaces and clean o-ring.  Surfaces with alcohol (91% is better that the 70% rubbing alcohol).  O-ring with dish detergent. let dry.   Next, take some high temp silicon seal (it has to be high temp stuff!!!!) and put a thin coating on surfaces.  Thin as in thinner than a credit card but thicker that a piece of paper.  Put together and let dry over night.  

The silicon will help fill the voids any imperfection might make.  Yet, silicon comes off fairly easy so you will be able to adj the valves at a later date.

Bobbert wrote on 04/11/08 at 12:03:25:

You're sure it's the valve cover? Because the dreaded Rubber Plug that covers the right front cylinder stud nut is right next to it.
This has been a source of leaks. You can see this plug with a flashlight.