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The left side is drip, drip, drip for several months now. I've done the 'tap-the-seal-washer' a couple of times to no avail, so it's time to replace the pair of leaky seals.

Question: When installing the replacement seals, does one use a smear of No.2 gasket sealer on the rubber seal mating surfaces, or silicone grease, or JB Weld , or nothing at all?

The factory used no additional sealant.

Most people suggest that a thin smear of some non hardening sealant be used. I recently did a top end on my /7 and used Permatex Ultra Grey. Yamaha Dreibond and Threebond are also used. Snowbum has a section at the top of this page:

http://bmwmotorcycletech.info/chemicalsetc.htm

Edit: I see that you specifically mentioned the rubber seals...I didn't see that. On my pushrod tube seals, I just used oil...actually, I think I used assembly lube.

Kurt in S.A.

In the beginning, I used some grease, but that was mostly to make the donut go in easier. Later we used the non-hardening stuff and it did both, lubricate and seal.

If you aren't finding any need to adjust valve often, and your head gasket is sealing well, then you can get away with just sliding the cylinder back a bit and replacing the donuts. In the shop, we almost always pulled it off for inspection.

I used a little silicone grease so the rubber could find its comfortable place.
Five years - no drips.

When are you doing this. My R65 needs it bad. I don't have the parts and I was gonna let it leak until the winter repair season (Jan-Feb), but I would enjoy helping/watching you to learn something. I did it on the R90 a few years ago, but I have slept since then.

bbelk wrote:When are you doing this. My R65 needs it bad. I don't have the parts and I was gonna let it leak until the winter repair season (Jan-Feb), but I would enjoy helping/watching you to learn something. I did it on the R90 a few years ago, but I have slept since then.

Ardy dun. I used a bit of silicone grease on the new seals. Little project took about three hours spread over about six hours time. (had to nap a couple of times.)

Let me know when you want to do yours.

dwerbil wrote:

bbelk wrote:When are you doing this. My R65 needs it bad. I don't have the parts and I was gonna let it leak until the winter repair season (Jan-Feb), but I would enjoy helping/watching you to learn something. I did it on the R90 a few years ago, but I have slept since then.

Ardy dun. I used a bit of silicone grease on the new seals. Little project took about three hours spread over about six hours time. (had to nap a couple of times.)

Let me know when you want to do yours.

Jan-Feb I guess.....

I remember our better mechanics such as GSPD and Funbags used to say no sealant. Clean thoroughly with petrol and assembled dry.
It appears to be OK to do both, sealant and no sealant.
The desire to use a sealant is understandable given the consequences of a leak/weep. No major problem, but who wants to see oil accumulating when it is avoidable.

So who uses a sealant and who doesn't?

I've gone clean and dry successfully over the years.

I do know I would pull the followers and inspect them for pitting as long as they were accessible.