baffling sound!

[Guest]

My 80 gs550 is makes an annoying buzzing sound in the right pipe from 3.5K to 5K - it's sounds good throughout the rest of the range. I checked for loose parts on the outside - the sound seems to be eminating from the inside of the pipe. A friend told me it's probably a loose baffle and there's nothing I can do about it. He doesn't know the power of thegsresources.com!

What troubleshooting can I do? I just got this baby up and running so it's always made this sound for me. Bike seems to perform well. Stock pipes.

[Nessism]

Did you do a carb sync? Not going to tighten up the baffle but can't hurt to make sure everything is running as smooth as possible.

[Dave8338]

If it truely is a baffle, there is little you can do to fix it without alot of work. Source another muffler on fleabay or change out your exhaust to a new V&H or similar. Good luck.

[smagnusen]

Did you do a carb sync? Not going to tighten up the baffle but can't hurt to make sure everything is running as smooth as possible.

I did do a carb sync, thanks nessism.

One thing that's been crawling around the back of my mind - I had trouble getting cam timing spot on with tdc. the #1 arrow is a little below horizontal at tdc. At horizontal the timing hashes are between tdc and 1F. I'm wondering if this could be causing any issues?

[smagnusen]

If it truely is a baffle, there is little you can do to fix it without alot of work. Source another muffler on fleabay or change out your exhaust to a new V&H or similar. Good luck.

Is there any way to check the baffles to confirm or dismiss them as the source?

[Dave8338]

Is there any way to check the baffles to confirm or dismiss them as the source?

Pull the suspect pipe and shake it. If the baffle is loose enough, you can hear it slap around.

[Nessism]

I did do a carb sync, thanks nessism.

One thing that's been crawling around the back of my mind - I had trouble getting cam timing spot on with tdc. the #1 arrow is a little below horizontal at tdc. At horizontal the timing hashes are between tdc and 1F. I'm wondering if this could be causing any issues?

It's normal for the marks to be off a smig. As long as the timing chain is not elongated you are fine. A couple degrees of camshaft timing is not going to cause excessive vibration anyway so don't worry.

[smagnusen]

Pull the suspect pipe and shake it. If the baffle is loose enough, you can hear it slap around.

Does the baffle extend from one end of the pipe to the other? If it rattles could it be quieted by welding the baffle end to the pipe. Lot's of speculation here I know.

[smagnusen]

It's normal for the marks to be off a smig. As long as the timing chain is not elongated you are fine. A couple degrees of camshaft timing is not going to cause excessive vibration anyway so don't worry.

Was hoping to hear that Nessism, thanks again.

[Dave8338]

Does the baffle extend from one end of the pipe to the other? If it rattles could it be quieted by welding the baffle end to the pipe. Lot's of speculation here I know.

Never had to dig into a GS exhaust, but on other bikes, the baffles have ranged from welded in, to riveted in, to completely removable. If in fact it is a baffle that has rusted loose over time, it is unlikely you'll be able to weld it back in place and get it to hold, though you never know. :?

[focus frenzy]

is the noise in the pipe or the muffler?

noise in muffler would be broke loose baffle, noise in pipe would be broken/ loose inner pipe as these use dual wall headers.

the standard GS exhaust system is welded together and is not easy to work on.

[pvtschultz]

I say replace with cheap (sometimes free) Harley mufflers.

[snowbeard]

having dealt with the inside of these pipes, the inner baffle is welded to the headers where the cone starts to flare. there's a weld on the cone and the baffle starts there too. it could be loose from the back end, or here, or maybe in the middle...

either way, you're probably not going to be able to weld it back without hacking open the whole thing. sorry (someone may be able to tell you something I don't know tho)

I took an extra set of headers that someone had cut the cones off a few inches from the end and most of the baffling was gone. I cut the cones a few inches behind the weld to the headers, then found the baffle pipe still in there, so had to cut it too, but I left it longer than the outer wrap of the cone.

actually wait, I have pictures!!

this is looking down the cone from the back with it cut halfway on the length of the cone. one pipe comes out of the header into the cone where it is split

Shot at 2006-11-12
this is after i cut the cone and most of the baffling, leaving some in case it came in handy, which it did...

Shot at 2006-11-12




i am not a welder... obviously. but I welded washers onto these to restrict the flow, since I didn't want to rejet. I ended up going to from 110 to 115 mains and kept the washers and it runs quite nicely.


so sometime later I rewelded these, change the cuts a little bit, and ended up using some short pieces of actual harley exhaust pipe, maybe 2 inches long, to attach the harley slipon turnouts that I wanted. I welded these better, then ground them till the harley pipe fit right over the baffle pipe, covering the leaks in the weld and also the drain hole that is in the baffle pipe down low. I plan to use that glue crap to seal it up someday soon, but it works fairly well for now, with a minor pop on decel sometimes because its' not sealed up well.


now that I've said all that, I know my salvage guy has at least two 550 complete sets. I could facilitate the purchase of one of them if you are interested and feel like paying shipping from Colorado on top of whatever he wants for them. just a thought.

[snowbeard]

oh, forgot to mention, I have had the bolt mounts rust out where the heat sheilds are bolted onto the pipes, it might seem tight, but in fact the "nut" has broken free. it could be this simple...

[smagnusen]

is the noise in the pipe or the muffler?

noise in muffler would be broke loose baffle, noise in pipe would be broken/ loose inner pipe as these use dual wall headers.

the standard GS exhaust system is welded together and is not easy to work on.

good point, not sure where the noise is coming from - will have to check somehow. The exhaust appears to be in good shape, no exterior rust, so it's hard to imagine the guts are too bad of shape either.