Exhaust Discussion

[Guest]

I have a GS1100GK, but my question is probably for all GS's. My OEM exhaust is in need of replacement. A PO at some point drilled into the side of one of the mufflers to remove the end cap and remove the baffles. That's my guess anyway. He learned from the first one and the second went a little better for him. In anycase JB Weld globbed on the side of my muffler is not attractive to say the least. So here is the question.

I would like to stay with the stock 4 / 2 look. I don't want to spend $300 - $400 dollars on someones used OEM pipes on Ebay. If I were going to do that I'd just spend the $300 on a new 4 /1 and be done. So, could I buy some after market mufflers and attach them and still retain the look? I want to stay with the stock airbox, and having read a lot of expert opinions on here about jetting and pods and exhaust, etc. I figured it was time to really ask the question I want the answer to. Some of you have a lot of experience building these bikes. I was looking at Dime City and some of the exhaust on there site. Some of it is the right length or close to it. Does anyone have experience with after market exhaust and these bikes? I don't want to buy a Harley muffler and rebuild the mounts to get something cobbled together that runs but sounds like something else. I want to buy something that looks period correct, or close to it that sounds more like a Suzuki should.

The knowledge I am looking for is in the fact I know from reading here if the back pressure is off on the exhaust and / or I go to pods I have to rejet. Is there a suitable aftermarket muffler I can buy and get the correct back pressure so that I won't need to rejet? I am worried that I may never get this bike running correctly if I have to rejet. I know it is a ramble, but I would really like to hear different opinions and finally hear a complete consensus for those of us that are not experts on the subject. It is quite confusing on the first bike build.

[Steve]

When my son got his first bike (an '81 450T), it also had muffler problems. We got a pair of the longer Dunstall look-alikes from JC Whitney. They mounted OK (universal clamp system) and looked OK and were affordable. The only 'complaint' that I had was about the sound. Granted, it was only a twin and sounded different than a Four, but I think the quality of the sound would still be there. It was not loud, it just sounded a bit 'tinny'. I have no idea how they affected jetting, that was very early in my GS career and I had no idea that I should be concerned about it.

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[dr_puter]

Exhaust

Thanks, Steve. Luckily I have access to experts like you to learn from. Otherwise I would be buying and trying. I would rather not go down that road. Since my mufflers are junk and almost straight pipes I have no idea what my GK is going to sound like. I remember what a 750 and a 650 sounded like. I remember flying into my GF's neighborhood pulling the clutch and the only thing i'd hear was the sound of the shocks as I hit her driveway. Quiet. I don't think the GK is going to be as sneaky quiet, but definitely don't want it to sound like it does now. Straight pipes are loud on an 1100.

[Steve]

Straight pipes are loud on an 1100.

Actually, straight pipes are loud on ANY bike, and there is really no good reason to have them.

Thank you for wanting to keep your bike quiet.

Click HERE to see those mufflers.

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[mainiac]

I just saw that mac has slip on replacement exhaust that fits on oem head pipes on gs 750's 77-80. They are priced around $300 a pair. Are these something new? I have'nt seen them before. I don't know if they would work on a 1100 or not. I am thinking of getting a pair as I really don't want a 4 into 1 ether.

[dr_puter]

Exhaust

That brings up another question. Will the mufflers from other models work on different models. I know you can purchase different clamps and reducers or weld it together, but will it work. If I found 850G Exhaust mufflers would they work on an 1100G or GK? Is it simply a fitment issue at that point?

[azr]

I bought the same Emgo Dunstalls for my 79 850G and had them welded to the headers. I really liked the look as it was close to stock but I never liked the loudness. I did manage to decrease the noise by wrapping them better with steel wool but I've always wondered if I could have had them even quieter if I had wrapped them with some proper muffler wrap. This is a timely discussion as I'm looking at the same issue for my 80 1000G. I can't believe we can't come up with a good alternative to old OEM systems. These guys have a number of muffler options http://www.mikesxs.net/products-44.html#products as well as these guys http://www.dimecitycycles.com/ but again a bunch of the mufflers are Emgo's, and it would be great to hear someone has used them here and had good results.

[dr_puter]

Exhaust

I am hoping more people jump in on this discussion as well. It would be really nice to have a few more opinions on this. I saw on another blog someone that was really familiar (or sounded like they were) discussing back pressure on exhaust, etc. I am sure it would effect twins more, but these GS's can be so finicky with carb adjustments based on airflow.

[dr_puter]

exhaust

I am still wondering what others are doing about this. I don't believe that everyone finds used exhaust or just automatically goes to a 4/1. Does anyone else have any experience with other aftermarket exhaust? Even if a rejet is required it seems there should be an answer out there.

[Steve]

If I found 850G Exhaust mufflers would they work on an 1100G or GK? Is it simply a fitment issue at that point?

That would depend on just how creative you want to be.

Last year, Dogma had a set of 850 pipes that he was trying to put on his 1000. He found that everything fit, except for the bolt spacing for the collars. The 1000's bolts are just a bit farther apart than the 850's. At the same time, I had come across a set of 1000 pipes that I was going to put on my 850. I saw Dogma's dilemma and suggested a swap. Now we both have pipes with which we are happy, and they both fit.

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[azr]

I really don't think this has been done too much. There are more expensive Dunstall type mufflers out there, ones that I would hope would have a better sound than the ones I have used in the past, maybe. I know the guy that has the set I had welded, I'm very tempted to ask him if I can rewrap them to see if it effects the sound.

[Gorminrider]

Not sure if this is pertinent to the subject,, but on a gsx400, I've just replaced old aftermarket chinese mufflers with newer aftermarket chinese mufflers from craigslist and they're fine, except the chrome is really cheapo and I had to shim the new set quite a bit for diameter. I really can't find any fault as to the running of the bike...
Having a two-cylinder bike with two pipes and mufflers (with an equalizing pipe between them!) surely makes me a non-expert, but my impression is that it's not so much the mufflers as the exhaust headers that affect your jetting and backpressures as an issue....ie: the differing bends and lengths.....?

[dr_puter]

Exhaust

"my impression is that it's not so much the mufflers as the exhaust headers that affect your jetting and backpressures as an issue....ie: the differing bends and lengths.....? "

If that piece could be confirmed as the answer to the question about backpressure and jetting for exhaust then I think it makes any muffler that fits the solution. At least as far as what to replace the OEM stuff with. Thank you very much for your contribution to this discussion.

[Steve]

I just love discussions that involve "backpressure".

The pressure inside the exhaust really doesn't do all that much.

What it does do is limit the amount of air flow, and THAT is what determines what jetting is necessary.

Along the same concept, there is no "airbox restriction" necessary for CV-type carbs to operate properly.
When you change to pods, you simply allow more air to flow, requiring re-jetting.

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[dr_puter]

Exhaust

Steve - Thank you for straightening me out. I think you are saying I do need exhaust, but backpressure is not an important factor.

So, I'll rephrase the original questions for the discussion:

Is there a known suitable aftermarket muffler I can buy and get the correct limited air flow so that I won't need to rejet?

Is there a known after market exhaust that does the above and sounds quiet, similar to OEM Suzuki?

Does anyone have experience with after market exhaust and these bigger bikes?

Is anyone with an 1100G or GK considering replacing their stock exhaust with a 4/1? Would you like to sell your stock exhaust?