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One of my 1977 R100S valve covers started weeping oil pretty badly.

I took it off. Noticed that the gasket was really stiff and crusty. I removed it and put a new one on only to find out that the problem is the center stud spinning inside the head.

While i was at it, I checked the valves only to find out that the other side was no better.

One side had a helicoil on it. The other side has a time sert. both seem to have failed. It's been 36000 miles so I guess I got a good run out of them. The Helicoil side will probably get fixed with a time sert. But the time sert side... It looks like the time serts outer threads have stripped in the head.

What can I do if the time sert fails? What is next? The next size up for a time sert? Or do they make something with a bigger Outside Diameter thread and still the M8 thread inside?

Get a longer metric threaded rod. Drop a nut inside the cavity behind the valve cover...the nut might need some trimming to fit. Use red Loctite and run the threaded rod into the nut. Look at using part 07-12-9-908-142...it's 70mm long. Be sure that it will all fit once the acorn nut is installed.

Kurt in S.A.

^
+1

Also, double gaskets worked for me. I gave up on the center studs and just used the two outboard 10mm.

I never did get around to trying the silicone gaskets.

Douph! Such a simple solution. Thanks. Sometimes the answer is too easy to see it!

I just ordered some M8 threaded Rod. It arrives on Saturday. If I can't Time Sert, then the rod will work.

I never heard of doing double gaskets though... humm...

When my center stud did the same and I pulled it out, I noticed that the threads were longer on one end than the other one. I screwed the longer threads into the head, caught some threads to hold it, and used the shorter ones on the nut end.

I've never had a problem but my observation is the studs are too short to fully engage the threads in the head and the nut. I screwed my in until they did fully engage the head threads and that left very few for the nut but steel on steel will cope better with that than steel in alloy.

The other issue is the nut needs to be very little above finger tight in order to do it's job. If I had to guess at a figure then it's under 5 ftlbs.

My dealer did the first thread repair on my R65 around the 2nd year.
I probably thought tightening it would solve an oil leak.

Rob wrote: ↑Thu Oct 19, 2017 6:34 pm My dealer did the first thread repair on my R65 around the 2nd year.
I probably thought tightening it would solve an oil leak.

Hello Rob, I feel that I am in the same boat. I have a peculiar oil leak on one side. I thought it was because that stud became loose. What was the cause and solution to yours?