Oil leaking from behind timing cover on /5

[duantro]

I've got some oil seeping out of the back side of the timing cover on the right side (when seated) of my Frankenstein r100/5. I've started taking it apart, but am waiting on a rotor puller tool from Dan at cycle works. Can anyone think of things to check when I get inside here?

[Bamboo812]

Good time to change the crank, cam and tach seals. Look for wear on the chain tensioner and gears, too. If the chain was really loose, you will see a notch worn in the case at upper left as viewed from the front.

[duantro]

Thanks for the suggestions. I have changed the timing chain, tensioner, and seals a few years back, and will for sure check them again. I'm hoping it is just a bad gasket that is causing the leak. I saw Robert snowbum recommends no sealer applied to the timing cover gasket. Does everyone agree?

[ME 109]

I saw Robert snowbum recommends no sealer applied to the timing cover gasket. Does everyone agree?

Yes. Check the mating surfaces for any small damage that could prevent the gasket from sealing.

[Foxy]

I replaced gasket on mine and leak stopped. Not sure why they decide to leak after years of being sealed. I think I used some sealer on new gasket.

[duantro]

I've finished replacing it. It looked like the old gasket had cracked. New one on and it seems to be good so far!