The New And Improved Unofficial R65 Forum V2
Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: Crossrodes on November 15, 2008, 05:45:29 PM
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'79 R65.... Two Questions
I noticed a hissing sound coming from the area of the right pot after a short ride a couple of days ago. This has happened before and I found that the spark plug was loose. So today with the engine cold I loosened and re-torqued the plugs. However they both seemed to be tight enough when I loosened them. Assuming I did have a plug that was on the loose side, what will cause them to loosen up and leak. I do use anti-seize on the plugs; will this cause a problem?
Second question....I noticed that once again I have an oil mist weeping around the base of the right pot. I had noticed this earlier this summer and tightening the head bolts seemed to take care of the problem when I did a valve adjustment. I've only put on about 5,000 km since I tightened the head bolts. Is it normal for the gaskets to start leaking again. Should I replace the gaskets or just re-torque the heads again? Should I expect to re-torque them this frequently?
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you should not have to re-torque the heads that frequently - ordinarily the engine doesn't weep at the base gaskets, but with many years or miles (or both) the gaskets do get tired. If you do decide to take the cylinders off to replace the base gaskets, also take the opportunity to replace the pushrod seals, as they will likely start to leak on ya after you get it back together if you won't replace them.
What type of plugs are you using ? I found on another bike (Yamaha) that I used to own that when I put anti-seize on the plugs and torqued them to spec, the metal gasket/washer at the bottom of the threaded section didn't compress sufficiently to seal it tightly. I noticed this after riding the bike for a while and the engine got good and hot, and I noticed some hissing/bubbling of the anti-seize compound around the base of the plug. I am not saying don't use anti-seize, but
some plug designs require more pressure to seal that metal 'gasket'. Go sparingly on the antiseize, I guess. I am not sure what else to suggest there.
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There are no gaskets on the base of our cylinders. Just a large, thin o-ring that goes arounf the base of the cylinder.
Perhaps this needs replaced?
Be careful on torquing those cylinders.
I've learned to live with a dirty engine. Better than pulled studs.
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Thanks for the replies/info guys. It looks like I'll be buying some parts. The plugs are NGK.
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Looking at the parts diagrams I'm guessing that I need cylinder head gaskets, rocker cover gaskets, pushrod seals. cylinder base O rings. Is there anything else that I will need and is there a kit I can buy from somone or will I have to order individual parts?
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You may not need rocker cover gaskets, they last a long time. You will also need the little O-rings between the upper stud holes/engine block. Check the rubber coupling between head and carb, if old hard/cracking this would be a good time to replace them. If your exhaust nuts have never been removed you might wind up cutting them off so maybe a new set of them as well.
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I'd be very careful about the exhaust nuts first. Hit them with several soakings of "Liquid Wrench" or "Blaster PB". Try to "ease" them off. Small increments of loosening, spraying, tightening, spraying, loosening, spraying, tightening, spraying, loosening, 'til they come off. If they give you a hard time, then (like Rob), I'd try to live with the minor "seeping.
If they come off easily (mine did) then go for it. Once they're off, and it comes apart, you can make up your list of needed parts.
Keep us posted.
Luck,
Ed (who still needs to seal his bike's jugs & push-rod tubes himself)
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Thanks for all your input. The exhaust nuts won't be a problem. I had them off a couple of months ago, cleaned up the threads and used anti-seize on them when I replaced them.
I should add that I try to anticipate what parts I will need and get them ordered because I've waited up to 3 weeks to get parts from some suppliers.
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'79 R65.... Two Questions
I noticed a hissing sound coming from the area of the right pot after a short ride a couple of days ago. <snip> ?
Pot = Right cylinder head? Might be water boiling between the rocker cover and the cylinder head. I am amazed that BMW would design something that collects water and dirt. Pain when it comes time to set the valve lash. :(