Exhaust and Header Questions

[Jcol]

Hello - The exhaust on my 81 has been an issue since I purchased the bike a few years ago. The cross over is gone and the PO filled the holes with muffler cement which actually has worked out ok. The drivers side has an exhaust leak right at the header/muffler connection. There is also some rust holes on the underside of one of the mufflers. Because of this I have been on the lookout for a replacement exhaust system. A pair of mufflers only came up locally a couple of months ago which I bought along with some other parts. On Saturday when we finally had a warm day I pulled the mufflers/headers from my bike and now I have some questions. First my mufflers and headers are welded together. I guess I knew this but my replacement mufflers look like they came from a system where they are inserted and possibly clamped to the header. Below are some pictures which show the mufflers and headers. So my questions are will these replacement mufflers attach to my headers? It looks to me like the end piece of the replacement mufflers is meant to slide inside of the header? I doesn't look like that would work with my headers. I know that in order to separate my headers and mufflers we would need to use a grinder however I don't want to end up damaging the end of the header etc. I'm thinking now I should put my old mufflers and headers back on the bike and try to find headers for my new mufflers and build up a complete second system. BTW I do not weld so if the new mufflers need to be welded to the any header I would have to take it to a shop somewhere. Any advise would be appreciated. Thanks.

 

[dan filipi]

I would build up the replacement system.
It looks like you'll need headers from a GL1000, they are clamped and not welded.

 

[brianinpa]

If you cannot find a set of 1000 headers you could make your 1100 headers work. On your stock system, cut the muffler off just in front of the cross over tube. That will give you enough internal pipe to use to clamp onto. Then you simply need to manufacture a connecting tube between the muffler and the header and clamp it up. Oh and my the way, no welding will be needed: just grinding. :whistling:

 

[joedrum]

plus one on what brian said

 

[tuna boy]

I am a little confused. Can the owner just clamp on OEM mufflers after cutting off the old OEM mufflers? How about the Harley big twin or sportster mufflers? It sounds like the sportster mufflers work better because the big twin mufflers have different baffels in the right and left. The quality and the price of the Harley stuff is excellent.

 

[brianinpa]

It isn't a direct clamp fit. A piece of pipe with the correct ID or OD is needed to either slip inside or outside the header and muffler. This thread over on goldwingdoc.com is about the best one I have found on the subject and there are several others linked within it. If you aren't a member, you may need to sign up in order to view it.

https://goldwingdocs.com/forum/viewtopic.php?f=3&t=9773

I bought a 78 parts bike last year and it came complete with a hardley sportster exhaust setup attachted to the 78 headers, so I am ready to go when ever I need it.

 

[zman]

I see headers for the 1100 come up quit freqently, Looks like a MAC muffler maybe, Jardine has a funky curved crossover tube.
Here`s a set pretty cheap.
https://www.ebay.com/itm/Honda-GL1100-Ex ... 22&vxp=mtr

 

[brianinpa]

If you go with the Sportster mufflers, I think anything pre-2003 is without a crossover tube, so that is one hole that does not need to be filled in.

 

[Jcol]

Thanks for all the great responses. I think I will go ahead and get some 1000 headers from eBay and make up the exhaust and keep my old headers and mufflers intact. Hopefully I'll have some pictures to post in a couple of weeks.

 

[tuna boy]

Is there a reason why you would be looking for pipes from a 1000. I do think some year headers work better but I don't know why. Something about the angle the pipes are made to? I am sure someone here know the reason you would pick one year over another. I think the 1000/1100 and 1200 headers are interchangeable.

 

[joedrum]

75-77 headers are different than 78-79 headers on 1000s ...the angle is different .... 1100s had no header its all one deal mufflers to head .... 1200s went back to headers ...

there are also after market headers ... personally I like the jardines that come out all singles to a collector ...instead of the two into one deal as all the others are ... :mrgreen:

 

[Jcol]

As an update I found a nice set of headers from an 84 on eBay which I should have in a few days. I'll report back after I build the system.

 

[ekvh]

The 1200 headers which I used on my 1200 in a 1000 frame were very tight to the frame where the sweep upwards. I cut and welded them to a straighter shot, but could have used a transition piece as well. Curious if yours will do that. I was under the impression that there were two styles of 1200 headers, like the 1000's, but I am not sure.

 

[Jcol]

Update: It's been sometime since I started this project but I just wanted to confirm that I did end up getting a set of headers from eBay and after some modifications I welded them to the new mufflers I obtained. When the headers arrived I was able to slip on the mufflers directly, but the length and the angles were all wrong. There was an upturn with the end section of the header which made the mufflers angle up instead of going straight back. I ended up cutting the end of the muffler of right back to the taper as well as taking some material off the end of the header. After doing this I was able to get the headers and the mufflers to fit together and get the mufflers to attach to the single bolt point below the passenger foot rest. At this point if got interesting. I have never welded before and no one in my area wanted to weld together the pipes unless I brought the bike to them. So an inexpensive Mig welder showed up on sale at Princess Auto (Harbor Freight in Canada) which I bought. There have been many times I have wanted to weld something. I played around with the welder on some practice pieces and ended up getting pretty comfortable with basic welding. Nothing pretty but it held together. At that point I ended up laying on my side and tacking the header and the mufflers together while they were on the bike and all lined up properly. There was no way I could have done it with the mufflers off the bike. After the tack job I removed the assembly and welded them completely around. The welds look fair to poor however 90% of it is hidden and the visiable part looks OK. The mufflers themselves are perfect and shine up nice so it is still a major improvement. As for the bike, the sound is only a little louder than with the original larger, rusty mufflers and I think the bike runs a little better. I just seems smoother and a little more responsive. Perhaps the shorter mufflers are less restrictive. I'm writing this at work and I thought I had access to some pictures that I was going to at to this post but I can't find them. I'll post them later today or tomorrow. All in all it was a fun up grade and it's a nice bonus that the bike seems to run a little better as well and I now have another toy (mig welder) to play with. thanks for all the suggestions and tips.

 

[joedrum]

great to hear everything is good

 

[ekvh]

Exactly what I did with mine. Without a transition piece you probably reduced the diameter on the outlet a bit, (not much, but if you cut a pie piece out, it has to be smaller at that spot) but with the free flowing muffler it probably is a good thing.

 

[Ansimp]

+1 :good:

 

[Steve83]

Cool! It would be great to be able to weld. Lookin' forward to your pics!

 

[Jcol]

Here are a couple of pictures. I always intend to take more during a project but I get caught up in the work and never do. The first picture shows the headers and the mufflers slipped on. I was hoping this would have worked however the angle and length were all wrong. Also note the snow in the back of the truck and on the ground :shock:


In order to make the headers and mufflers fit I ended up cutting off the short straight section on the muffler back all the way to the taper. I left about a half inch of the straight part. I also cut off most of the straight part of the header. When assembled the taper on the muffler is almost up to the start of the straight part of the header. This got me short enough to get the mount bolt to line up and allowed me to reduce the angle so that the mufflers run straight back, not angled up. I had to tack this together while it was on the bike, and them remove and finish the weld job. Here is a picture of the finished mufflers and headers on the bike. Notice I did not focus on my weld job as it is more or less hidden anyway. These mufflers and headers are a great improvement looks wise from my old rusty setup.

 

[Steve83]

Very nice! How do they sound?