Hi all,
Does anyone know where to install muffler packing in a 1975 muffler? Here is what I do know - The outlets on each side contain a removable perforated cylindrical baffle. Originally the baffle was packed with a rockwool type material (state of the art in 1975).
I purchased a very used original muffler. When I opened the two halves of the shell, I found loose rockwool in the chambers near the inlet. I'm not certain if there is supposed to be packing in this areas or not.
Question: Other than the perforated discharge baffles, should I install packing material in any other chamber of the muffler?
Here what I found when I split the top and bottom halves of my very used muffler.
Repacking a 1975 GL1000 Muffler
- Maz
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1976 CB500T
1979 CB750L
1990 Yamaha FJ1200
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Re: Repacking a 1975 GL1000 Muffler
It might be worth emailing the company in the UK that makes fantastic reproduction GL1000 exhausts - NHC Panels ltd. I think they distribute them in the US via a company called Sirius inc. The details are on Randakks site, though.
Maz
Maz
Ironically, Common Sense is the LEAST common of all senses!
- DenverWinger
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1980 GL1100 STD Vetter (2005-)
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Past rides
1972 CL350 (1980-1988) sold
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Re: Repacking a 1975 GL1000 Muffler
To be honest, that "Packing" looks to me like "Mr. & Mrs. Mouse" were raising the Mouse family in there. I don't think that belongs in there, if you test it with a match it probably burns.
Interesting to see the inside of the GL1000 muffler, now I can see why the GL1000 I had was so much quieter than my 1100....
Interesting to see the inside of the GL1000 muffler, now I can see why the GL1000 I had was so much quieter than my 1100....

There are 10 types of people in the world, those that understand binary numbers, and those that don't.
♫ 99 Little Bugs in the Code, ♪
♪ 99 Bugs in the Code. ♫
♫ Take one down, Patch it around, ♪
♫ 127 Little Bugs in the Code. ♫ ♪
~Mark

♫ 99 Little Bugs in the Code, ♪
♪ 99 Bugs in the Code. ♫

♫ Take one down, Patch it around, ♪
♫ 127 Little Bugs in the Code. ♫ ♪

~Mark
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Re: Repacking a 1975 GL1000 Muffler
Thanks for your reply
Now that you say that, it seems very logical that my muffler turned into a mouse B&B. It also explains the loose wool type material and how it was placed so far upstream of the exhaust flow. If this is the case, then the only packing material in the '75 muffler must be the missing fiberglass mat surrounding the removable baffles.
Now that you say that, it seems very logical that my muffler turned into a mouse B&B. It also explains the loose wool type material and how it was placed so far upstream of the exhaust flow. If this is the case, then the only packing material in the '75 muffler must be the missing fiberglass mat surrounding the removable baffles.
- GL1000K1dan
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Re: Repacking a 1975 GL1000 Muffler
Hi NewGWguy
It's good to see the internals of the silencer so thanks for posting the pictures.
Out of interest, how did you open it up and how were you intending to close it up ?
It's good to see the internals of the silencer so thanks for posting the pictures.
Out of interest, how did you open it up and how were you intending to close it up ?
-
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- Joined: Thu Oct 10, 2019 7:34 pm
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- Motorcycle: 1975 GL1000 (Frame Off Restoration Underway)
Re: Repacking a 1975 GL1000 Muffler
I covered this in a little more detail in a parallel posting on the Reference Information forum. In a nutshell, the two halves are welded together with a thin bead around the perimeter of the housing. The weld is at the outer edge of a "lip" in the upper and lower half. A handheld grinder makes short work of removing the bead and leaving sufficient lip to reattach. The housing is reassembled by lining up the lips on each half and welding a new bead along the perimeter. It is clearly a labor of love as the rewelding and patching rust holes from the inside will take a bit of time.
I have already purchased the recommended Harley-Davidson replacement mufflers. Mostly, I was curious what the inside of the '75 - '76 mufflers looked like.
I have already purchased the recommended Harley-Davidson replacement mufflers. Mostly, I was curious what the inside of the '75 - '76 mufflers looked like.
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Re: Repacking a 1975 GL1000 Muffler
The company in UK.. Nhc panels is no longer.. Closed its doors about a year or so back. It's a shame but I guess there is a limited market for them. And even more tight arses that don't want to pay for quality yet whinge about the quality and services from certain online shops...
I would've like to know where their moulds went for that system tho....
Im trying to find someone here in Australia that would press out the 2 halves... I have a donor exhaust if I find someone...
I would've like to know where their moulds went for that system tho....
Im trying to find someone here in Australia that would press out the 2 halves... I have a donor exhaust if I find someone...
- offcenter
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76 GL-1000
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Re: Repacking a 1975 GL1000 Muffler
I was just about to say the same thing.DenverWinger wrote: ↑Wed Dec 30, 2020 5:08 pm To be honest, that "Packing" looks to me like "Mr. & Mrs. Mouse" were raising the Mouse family in there. I don't think that belongs in there, if you test it with a match it probably burns.
George in Jersey.
99 Goldwing GL-1500 SE
76 Goldwing Gl-1000
77 Honda CT-90 "Trail 90"
99 Goldwing GL-1500 SE
76 Goldwing Gl-1000
77 Honda CT-90 "Trail 90"
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Re: Repacking a 1975 GL1000 Muffler
They do not make and sell that muffler any more. I tried to buy one and they said "sorry'.