1978 GS550 Mufflers debaffled

[Anonymous]

Has anyone removed the baffels from the stock mufflers. If I usea hole saw and cut the rears will the baffels come out?? Thanks Again

Steve

[SqDancerLynn1]

Yes they will come out & then your mufflers will be totally useless & yourbike will run like S%$#

[earlfor]

Listen to Lynn. He's right Y'know.

Earl

[Anonymous]

Yes they will come out & then your mufflers will be totally useless & yourbike will run like S%$#

Thanks guys I'll leave them alone then..LOL..

[earlfor]

GOOOOOOOD CALL! :-) :-) :-) Unless of course you enjoy #@#$$%$!!

LOL

Earl

Thanks guys I'll leave them alone then..LOL..

[Anonymous]

Okay, I'm one of those people who needs to know why. Not that I have any reason to agree or disagree with the advice offered (I am ignorant, obviously, of what makes mufflers tick), but I like to understand the theory/rationale behind something. For example, is it the baffles in particular? What if there was fiberglass packing but that was all you removed and you left the baffles? What if you replace the old muffler with a newer muffler that has baffles, but that have a different configuration (e.g., fewer cutouts, or 120 degree offsets rather than 90 degrees)? Is the megaphone shape critical to the effect of removing the baffles, but what if you went to a simple straight pipe and minus baffles but with one of those simple fiberglass packing kits? There's probably a lot of ground to cover here, but it would be helpful for me if I could learn what happens and why when the dynamics change in the pipe/muffler system. Thanks in advance for any illumination cast my way...

...Ross

[Nerobro]

My bike has gutted mufflers. Don't do it. It cuases serious lean issues. If you DO do it. You need to rejet.

[AOD]

Cincinnati-Jim had no baffles on his 550, with stock exhaust, and it was pretty freaking loud. I'm not sure if he re-jetted or not.

[Nerobro]

it's neighbor angering loud.

[Anonymous]

I don't remember Jim-Cinni's 550 being real, real loud :? , but is sure sounds good carving up the curves 8)

[Anonymous]

There are baffles in the muffler, but it does not have any sort of fiberglass or other fabric like packing stuffed in or wrapped around the baffles. Presumably it will be louder than if it had packing, but how will other issues (e.g., backpressure relative to an old, rusty, wornout and barely functional original megaphone muffler) affect the bike's performance? Thanks again for your thoughts...

...Ross

[Anonymous]

Hi,

This is my first post so go easy on me..

I have been doing a lot of reading in the forum and learning lots about my first bike 81 GS 550 L. I was thinking about changing the last half of the exhaust / bafflers basically for cosmetic reasons.

They have small rust holes on each side. I was going to replace with them with some 15 inch turned out exhaust tips from JC Whitney. After reading the forums, I am seeing that I could cause more headaches for myself. (correct????)

I am guessing due to the new back pressure? I will keep reading but can someone direct me the forum on jetting. I am still new to this. If I can handle cleaning my carbs, can I handle this project?

Thanks

[Anonymous]

Welcome, Razor. I'm pretty much a newbie here myself, but it is an incredible forum with an amazing amount of knowledge. Imagine the National Archives of GS Motorcycles, but maybe not as well cross-indexed.

I have the same model bike as you but mine's a year older. The most important "challenge" you will run into on the original 550L mufflers is (unless a previous owner changed this) they are welded to and part of the exhaust pipes. This leaves you two choices: buy an all new 2-1 or 4-1 exhaust system; or adapt what you've got. I went the latter route and had a welder cut off the old mufflers and weld in 10-inch stubs to which I can now attach slip-ons. I also liked the look of the 20-inch turnouts; the ones I got have a stainless steel baffle in them, so it should last quite a while. However, there is no packing material.

The bike sounds really a lot better, has a better-flatter throttle response across all RPM ranges, and has way more oomph in acceleration. The downside however is there was a significant reduction in backpressure, causing it to run way too lean in the higher RPMs (i.e., as you move past half-throttle) and risking much piston damage. Folks on this forum convinced me the correct next step was to get the carburetors rejetted (just the mains). Since I know for a fact that the carburetors have never been seriously touched (i.e., cleaned, soaked, new o-rings, fine tuned, etc.) in 25 years, I decided to combine the rejetting and full carb reconditioning.

As I've said before here, though, I practice the do-no-harm approach to performing my own work on my bike. So, I have hired out the carb rebuild and rejetting to someone I trust much more than me. In your case, doing it yourself may make more sense. Bottom line though, if you change out your old mufflers and don't replace them with essentially identical megaphones, you will probably need to work on the carbs.

For rejetting questions, use the "Search" feature provided in this Forum. Also, go through the Old Q&A section and just read, read, read. A wealth of tips and info there. Good luck and don't forget to have fun...

...Ross

[Rico]

While we GS owners have bullet proof powerplants in our rides they are very temprementle (sp)

The exhaust/fuel/air mix is one that few should jack with.
I'm not saying DON'T I'm saying be ready for a can of worms.

I've been lucky that all my mods have come together (with help from this forum) but a few special tools a handfull of manuals not to mention a full shop does help.

Don't be afraid but be learned.

Rico

ps Tyger were abouts are you in WA state? I'm always looking for someone to ride with

[Anonymous]

yeah this forum is a great place. for help, parts, tech info, and general fun with others who own similar bikes. i have just recently started running into carburetor problems. either they need ot be synched or hte hole in the left exhaust pipe is causing trouble. either way, i need to get some work done, and source some parts. glad to see that there are a few more people in WA than when i initially came to this board. should put in some spare time to meet up!