Topic: Oil leak, 750 F2

[frodef2]

Lately my CB750 f2 have started to leak oil from the head area.
this is the leak seen from the carb side.

This is from the exhaust side.


The number 3 sparkplug hole looks like its wet from oil.

After searching on this forum for possible areas to leak from I decided that the most likely suspect was the rubber seals under the cam holders. when i took off the cam, all seals seemed to be in place. the seals are not all flat, but kinda bulging.

All the seals where inserted in the holes with the bulge down in the hole. should it be the other way?

Are there any other possible sources for this leak?

[rbmgf7]

yes, the bulge should be downward.

could just be 30 year old gaskets giving up (valve and head gasket). it's pretty common.

[bwaller]

Those rubber pucks are flat when new. They compress and bulge in the middle with time and heat. They should be changed automatically when you replace the gaskets etc. which you should do now that you've pulled the engine!