The New And Improved Unofficial R65 Forum V2

Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: 79beem on May 07, 2013, 01:05:27 AM

Title: Push rod seals, base O-rings etc
Post by: 79beem on May 07, 2013, 01:05:27 AM

Soon to dive into this job as the oil leaks are getting worse.

I'm wondering if its worth messing with the heads or is it best to take them to my BM mech for inspection/service?

I have all the measuring gear.

I have 150-155 psi in both pots so is it safe to assume I can leave the pistons/bores/rings well alone?

I will check the piston pin OD, con rod bore,push rods, cam lifters and decarbon the pistons. Does varnishing look like.... varnish? [smiley=idea2.gif]

Between Snowbum,clymer and Chris Harris (youtube) I think I have all the bases covered.

Snowbum does recommend the use of a very thin application of high temp rtv sealant at the base of the cylinder even with a new and oiled O-ring. ( avoiding oil passages on top studs ).

I have bought two cylinder base gaskets (not shimms), but I'm not so sure about this as I would imagine it would produce a drop in psi and limit the effect/need of the O-ring's. The bike is particularly leaky at the right cylinder base.  Nuts are torqued.

Any thoughts advice on any/all of this?

Anything else I should be looking at?

Title: Re: Push rod seals, base O-rings etc
Post by: bruce_launceston on May 07, 2013, 05:11:14 AM

I believe that adding a rtv sealant to the base is not worth the risk, the oilways could be easily blocked, trust the new 'o' ring to do it's job.

Title: Re: Push rod seals, base O-rings etc
Post by: montmil on May 07, 2013, 06:04:55 PM

YamaBond for the sealant. Easily sourced and just a little dab will do ya.

Title: Re: Push rod seals, base O-rings etc
Post by: nhmaf on May 07, 2013, 10:22:24 PM

Yes, just keep away from the top oil channel studs with the sealant, and only apply a very thin even schmear - just enough so that you can tell that you wiped it off if you pass your finger across it