BMW R100RS leaking rocker cover

Make sure both surfaces are flat and true, use a new gasket, with no sealer, and clean the surface well with lacquer thinner or brake cleaner before assembly. Get the surfaces clean and DRY! I have used this method many times over the years and any time I have removed the part later the gasket was well adhered to both surfaces. Greg

Thanks Greg and Don, the gasket was new and surfaces clean but not with thinners or brake cleaner. Think I'll take it off again and clean thoroughly and then either (a) make up own thicker gasket from cork (like the old days!) (b) reuse fitted gasket which is almost new and use something like Cat gasket cement or (c) thoroughly reclean, sand and see how that goes. Thanks again, regards, Mac

You know that this unique motorcycle with heated food pegs .. er .. the boxer, tends to fall on the covers (depending on the drivers skills). Thus, they get easily warped. You either have to check that they are flat (the covers, not the head) or (if they are flat) use a decend sealing like hylomar or my beloved Locktite 5205 (or a number quite near that). As others sayd, no big deal getting it flat on a sanding paper.

Nick, from BMW-town Munich

You probably have a porosity in the cover somewhere. Possibly in the head. Has the bike been down on it's side ever?

To put this in perspective, I've got 4 bmws in various shape. Nearly every one has some buggering on the valve covers, some have been ground flat on the outside and are visibly starred on the inside.

I *never* change the gasket when I do valves. The bikes get ONE valve cover gasket and it pretty much gets reused for the life of the bike. The surfaces on the head and the cover are pretty rough - and the gaskets never leak at that interface.

One way to pin down *exactly* where the leak originates is to clean it off really well, and the spray on some foot powder from one of those spray cans. It will turn everything white and you can see exactly where the problem starts.

Your RS probably has the black square ones, right? If you find that there's a porosity, post back because I never did like the square ones, and put repro round ones on my RS from Bobs.

Jim

If all else fails, cover the Beemer insignia with H-D emblems to explain the oil leak.

I was aghast to find a small drip from my R90/6 due to a pan gasket leak.

David

My Harley does *not* leak oil ! It marks it's territory ...

I've got a 1995 H-D FLHTP with 155,000+ miles on it that's never leaked a drop of oil. I've also got a '37 H-D EL that makes up for it .

In any event, one has to determine th' exact location of a leak before fixing it can be addressed. Until that is known, all we can do is guess as to why and how to stop it. Who knows, maybe putting a Harley emblem in th' right place would work, heh, heh.

Snarl

The newer bike can be expected to be tight, it's no suprise the EL (you own a *knucklehead*??) isn't.

But he R90/6 shares more in common with the EL than anything else. The pan gasket is cork, and the bolts holding it on go through into the sump. Unless the bolt threads are sealed, the bolts that are through-holes *will* weep.

Likewise the rear main seal on those things is never quite right. BMW has gone through about 5 fixes over the years. Each one was

The good news is, those bike run just fine with weepy rear main seals. My oldest bike used to have a small wad of paper towels stuffed up under the gearbox. Change the diaper every week and it never left a mark.

Jim

Yes Sir, it's a pretty much stock 61 ci Knuck. Anything can be made to be oil leak free if one is anal and motivated enough to go there. Truth be told, I'm still rather amused when I look under th' 1995 and see *no* leaks.

Until it runs out of oil . And I'll bet you a libation of choice that given th' time and materials, you could come up with a leakproof fastening design for that application too. Question is, is it worth it?

Only took about 80 years for H-D to cure th' primary leak issue, heh, heh.

There ya go! Low tech, easy, effective and cheap.

It appears th' OP has received some good advice on his leaking problem. How far he's willing to go to solve it is yet to be known. Good luck to him.

Snarl

Heh. I just coat the M6 screws that hold the sump on with RTV before putting it together. Seems to work!

Jim

And they, like dogs..love riding in the back of a pickup truck

Gunner

"Pax Americana is a philosophy. Hardly an empire. Making sure other people play nice and dont kill each other (and us) off in job lots is hardly empire building, particularly when you give them self determination under "play nice" rules.

Think of it as having your older brother knock the s*it out of you for torturing the cat." Gunner

Use "Indian Head gasket shellac". Very similar to the stuff Holley carbs used to use with its carb gaskets. Spray on both sides of new vc gasket, let dry and wipe all seating surfaces clean of oil before reassembling. My R60/5 used to leak in this fashion before I did this. BMW was a bit shy in using fasteners I guess. How did they expect a "wet" cover to seal with just 1 main bolt and a couple of "hidden" 10mm nuts on studs.

I had that Beemer howling at 30 honest HP on a dyno. 38MM Dell'orto pumpers with oversize valves and ported intake and exhaust on the heads. Oh yea, shaved about 4 lbs off the flywheel as well.

Last I heard some moron who ended up owning it broke both pistons at the wrist pin putting crap gas in it. When it pings loud enough to hear it over the exhaust, you need to back off until you get some real gas. (Premium or better.) SIGH!

Bart D. Hull snipped-for-privacy@inficad.com Tempe, Arizona

Check

Remove -nospam to reply via email.

snipped-for-privacy@ozemail.com.au wrote:

I knew it... you owe me a pair of ice cold Coors .

Snarl

G'day, thanks to all for the advice, trying to get some time, maybe tomorrow (Tues 6th) with a bit of luck. Regards, Mac

Wait a minute, Aren't these machines touted for treks through Greater Asia? The Cape? Tierra del Fuego? Malibu? ANWR?

Didn't Porsche solve HD's engine problems by starting from scratch with a new engine?

Nick

You can't get gas good enough to run those bikes with the heads the manufacturer put on them. When I could get 95 octane it was OK, after they went down to 93 I had to put thicker base gaskets on the bikes. Either that or dual-plug. When I tore the one bike down I did find cracks in the pin bosses of the pistons. Not a good situation.

Jim

Hey Gunner, this is 2005 man. Pickups are so yesterday, these days they like to ride inside $100k double decker, enclosed trailers that have a matching $100k paint job as th' $1M diesel pusher motorhome that's pullin' it. Guess you haven't been to Sturgis lately .

Snarl