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Muffler mounting R75/5

Quidger
Posts: 25
Joined: Fri May 11, 2012 9:17 pm

Re: Muffler mounting R75/5

Post by Quidger »

srankin,
The left axle sits just under the muffler as you describe. The right muffler bracket lines up perfectly. The left shock absorber mounting bolt lines up in the middle of the muffler and prevents the muffler bracket holes from lining up with the threaded mounting holes on the sun frame. My swingarm is aligned perfectly so I don’t see a way that I can effectively move the shock bolt the extra 1/2” that is needed to get the mounting holes to line up.

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srankin
Posts: 726
Joined: Fri Jul 14, 2017 8:45 pm
Location: Spencerport, NY USA

Re: Muffler mounting R75/5

Post by srankin »

I have looked at the pictures several times, enlarged them. Sorry, I can't see anything amiss.

Okay, stupid question, are these the mufflers that were on it originally and did they fit then?

Is the left header pipe bent? is it parallel to the right? Have you tired reassembling the headers and crossover.

I am sorry, I just can't see the solution. More pictures might help? St.
Owner of a 84, R80RT and 78, R100RS

Quidger
Posts: 25
Joined: Fri May 11, 2012 9:17 pm

Re: Muffler mounting R75/5

Post by Quidger »

https://photos.app.goo.gl/KzvpqbYkL96XxHun9

See if this link to Google photos works.

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srankin
Posts: 726
Joined: Fri Jul 14, 2017 8:45 pm
Location: Spencerport, NY USA

Re: Muffler mounting R75/5

Post by srankin »

The additional pictures help a lot in identifying the problem. I will ask again, were these the original mufflers, were they at one time installed on the bike.

I am looking at the picture you have of the pipe behind the foot peg. I am not familiar with the way the pipe bends up and it looks like the muffler is slipped onto the pipe differently than I am familiar with, a red flag.

The second picture of the muffler and the axle is another red flag in my mind, Most of the mufflers I have seen have an indent where the axle can slide out without removing the muffler. I don't see this on this muffler?

I don't see anything wrong with the shock mount or the bolt you are using.

So, are these the correct mufflers for this bike? From what I can see no, or the header pipes are not the right ones.

Someone with a R75/5 will have to chime in and send pictures of their bike's mufflers. Sorry I can't say more, St.
Owner of a 84, R80RT and 78, R100RS

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schrader7032
Posts: 8464
Joined: Fri Oct 27, 2006 3:00 am
Location: San Antonio, TX

Re: Muffler mounting R75/5

Post by schrader7032 »

Compare you bike and muffler orientation with the ones from the page:

http://www.bmbikes.co.uk/photopages/photosr75-5.htm
Kurt in S.A.
'78 R100/7 '69 R69S '52 R25/2
Fast. Neat. Average. Friendly. Good. Good.

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srankin
Posts: 726
Joined: Fri Jul 14, 2017 8:45 pm
Location: Spencerport, NY USA

Re: Muffler mounting R75/5

Post by srankin »

I found some pictures on Recycle's used bikes for sale pictures I may be seeing things but I see the bike there doesn't have as much of an upward bend as I am seeing in your pictures? St.

https://repsyclebmw.picturepush.com/sho ... clid=16252
Owner of a 84, R80RT and 78, R100RS

Quidger
Posts: 25
Joined: Fri May 11, 2012 9:17 pm

Re: Muffler mounting R75/5

Post by Quidger »

The mufflers are the originals that came on the bike. I’ve concluded that, even though it is not perceptible to the eye, at some point in the bike’s life the left header may have been slightly tweaked or bent. By pushing the attached muffler with slight pressure and holding it in place with a sliding clamp I can get the holes on the muffler’s mounting plate to align with the threaded holes on the swing arm.
Thanks for your input ad sharing your knowledge.

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Randolph
Posts: 63
Joined: Tue Jan 13, 2015 11:31 pm

Re: Muffler mounting R75/5

Post by Randolph »

Sometimes I fail to seat the header pipe FULLY into the head. I feel better with a love tap from a rubber mallet and hear the "clink" of the pipe hitting home.

-Randy

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srankin
Posts: 726
Joined: Fri Jul 14, 2017 8:45 pm
Location: Spencerport, NY USA

Re: Muffler mounting R75/5

Post by srankin »

Sorry to be a pain but I would agree with you the left header is bent. It is hard to see in your picture but, I can see it. LOL, I have to look hard. Looking at the various pictures posted from other sources of bike, you should be able to see the difference.

At least you are able to get things lined up and together. I don't know if you could bend the pipe back or not? Really if you don't have to, things are together don't worry, just ride. St.
Owner of a 84, R80RT and 78, R100RS

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cbclemmens
Posts: 98
Joined: Sun Apr 25, 2021 2:21 pm
Location: Apollo, PA

Re: Muffler mounting R75/5

Post by cbclemmens »

Quidger;

I think those are not stock mufflers. I have a '71 R75/5 with the original stock mufflers. From your photos they appear quite different. Some photos of mine are below. Aside from the fact that mine are still dirty are several weeks of riding, the bends to accommodate the axel and shocks on mine arrear to be absent on yours.

Craig
IMG_4377.JPG
IMG_4373.JPG
IMG_4374.JPG
IMG_4375.JPG
IMG_4376.JPG

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