The New And Improved Unofficial R65 Forum V2
Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: peteremc on August 13, 2016, 10:17:58 PM
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I removed my exhaust system probably about 12 months ago. Stored all parts in just the way they were removed from the bike. Trying to refit the exhaust now and I find it will not tight up into the head properly. It came off with one clamp ring inside the spider nut.
Both my manuals (Haynes and Clymer) make reference to an inner "compression ring" fitted with flat side against the head and tapered side pointing out, and also an outer "clamp ring" mounted the opposite way i.e. flat side against spider nut and tapered side pointing in, so that the tapered surfaces of both rings meet.
I've checked 2 parts diagrams for the R65LS and both only show one ring called a clamp ring.
Another ring in there will certainly fill the space to tighten up the exhaust, but I'm certain there wasn't one when it came off. Any advice from the gurus?
Thanks
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Did you remove the entire exhaust system in one piece, just removing the finned nuts on the cylinder heads ??
The header pipes and cross over pipes still assembled ??
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When I removed it all, from memory, I removed the mufflers first, then loosened off the spider nuts, then undid the support clamps each side and finally undid the spider nuts the rest of the way and slid the spider nut and one ring on each side back down the headers so that I knew which way the rings went back in, and then removed the system in one piece with crossovers in place and put it on the shelf.
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Hello Peter,
There is only one seal ring on the R65. It is real thick and sits tight on the tube .
IMHO your exhaust tubing is not properly set and this is what prevent the winged nut to go all the way to seal the job.
I use a dab of anti-seize grease to help it slip in place.
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Hello Peter,
There is only one seal ring on the R65.
Mine has a two piece part just like earlier/bigger models - clamping pressure forces one smaller to gas seal.
As far as I know there was only ever one year mode that had a single seal ring and BMW quickly gave it up as a bad idea. BUT my memory tells me that was an R80.
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Well my '82 R65 has only one ring there. It is really thick.
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My 85 R65 has one thick ring, flat slide flush to the head. Use heaps of copperease and ensure the headers are seated in as far as they can go with a tap and wiggle. (There is a small rim inside the head.)
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Thanks georgesgiralt. That’s the same diagram I looked at.
Thanks Tony, but it sounds like more than one year model has only one ring.
The way mine came off was with the flat side of the single ring against the spider nut and the taper pointing at the head.
georgesgiralt I would guess that the 82 R65 is the same as the 82 LS model. Would you know which way around your single ring is fitted i.e. flat side against the head with tapered side pointing out or the other way around?
To me, if there was only one ring, it would be intuitive to have the flat side against the head and have the end of the header pipe mate up to the taper to form a seal - and Kookaburra has confirmed that his is fitted this way.
I had no problem getting the header in to where it is supposed to go. The problem I had was that when I did up the spider nut fairly tight, the header was a really sloppy fit.
When I get time I may try fitting the ring with flat side against the head and see how that goes but meantime, any advice I can get ….
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Hello !
The tapered end goes to the winged nut. It makes sense because the tapper is for the ring to be closed when the nut is torqued. There is a rim inside the port on the head to stop the ring axialy. This way when the nut is serrated, it is forced to close it's gap and seize the header.
I hope I'm clear enough...
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My thoughts exactly. I'll fit it this way and see how it goes.
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Insure the header pipes are fully seated into the head. With the staggered cylinders of the Airheads, and fitting both pipes at the same time, the headers can become slightly cocked and give the false impression of being fully seated.
I also remove the headers as a unit. Prior to refit, I will clean the ends and give them some love with an anti-seize paste. I do find that side-to-side gentle love taps from a rubber mallet are helpful.
Use great care with the butterfly nuts. Do Not go all medival with the proper exhaust nut wrench. Stripped exhaust port threads can be terribly expensive to repair. If it won't, don't force it. Determine what's preventing a smooth assembly.
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The first time I removed the exhaust system on my '81 R65, I removed it as you did, but upon reassembly, I could not get the header pipes back into the heads, until I got the crossover pipes broke free from the header pipes .
Then it went back together with no issue .
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Thanks all. As I said, no problems getting the pipes in and they seem to seat properly. The problem was that once they were in and the winged nut was tightened, the pipes were still loose in the head. So, I did a quick fit this evening with the ring reversed (now with flat side against the head) and tightened the wing nut by hand and it was a whole different feel, so think I'm on the right track.
Thanks again
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According to the diagram there appears to be "2" crossover pipes: one at the front and one that must connect just ahead of the mufflers. Is this accurate for all years?
I'm asking because my '87 was a California model and has a catalytic converter that I want to get rid of and replace with new headers, but all the ones I've found just come with a single crossover at the front.
Which one is correct and does it matter if there is only one?
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According to the diagram there appears to be "2" crossover pipes: one at the front and one that must connect just ahead of the mufflers. Is this accurate for all years?
No
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According to the diagram there appears to be "2" crossover pipes: one at the front and one that must connect just ahead of the mufflers. Is this accurate for all years?
I'm asking because my '87 was a California model and has a catalytic converter that I want to get rid of and replace with new headers, but all the ones I've found just come with a single crossover at the front.
Which one is correct and does it matter if there is only one?
Not to me it doesn't. My 1983 R65 had some nasty header pies and ghetto clamped x-overs where the OEM pinch-clamps used to be. Rusted away they were.
I got out my metal cutting tools and removed the x-over tubes completely. Cut and ground away the stubby tubes on the headers. Used the x-over tubing to cut and shape patches that were then TIG welded onto the header pipes. A little gentle touch up with a grinder and I called it done. Ultimately, I added EMGO Dunstall repop mufflers and used a tan fiberglas heat wrap material and stainless zipties to cover the ugly headers.
No difference in performance at all. I've heard and read so many different and usually unsubstantiated reasons for the single and/or dual cross-over pipes that I quit worrying about it.