Quieter Mufflers?

[Solonys]

Hey everyone!

The "beloved" PO of my 79 special drilled 4 additional holes into the back of each of my mufflers, and the noise is getting to myself and the neighbors (especially early morning when I go to work). I am personally not of the mind that "Loud Pipes Save Lives", and want a quiet set; aside from Harley Take-offs from the local dealership, does anyone have any recommendation for quiet mufflers? I am not afraid of making brackets/welding/that sort of thing if needed.

Hopefully I can quiet the girl down, because then I'll be able to hear all the other noises I need to fix!

Thanks in advance!

[jetmechmarty]

The stock exhaust is getting pretty rare and aftermarket options are almost zero. Weld up the holes or hire someone to do it. That's what I would do if it were mine.

[Socer4m]

Hi Solonys,,,,easiest is to just patch up the holes,,,either weld or get some metal filler like jb weld,,,,clean the area good with gritty sandpaper, fill it, let dry and it will sound good again. If the holes are huge,,,,definately weld some plate over the holes and then metal filler to look good, with a quick spray paint and voila,,,back to normal. My son did exactly the same thing,,,,made louder, lost a lot of low and high end power,,,,we filled the holes back up and it was back to normal,,,,,,,,,,,harley takeoffs sound great, by the way,,,,more work, but if you like a nice rumble to the bike, its perfect....let us know what you do,,,,,Mike in San DIego

[drdwb]

Back in the day when I bought my new 1979 XS 750 Special, it was recommended to drill 3-4 holes into the back of the muffler to allow excess moisture to escape, the rationale was that the reason Japanese mufflers all rusted out was a build up of moisture that got trapped, so the fix was to drill 1/8” holes about 1/4” apart along the bottom of the back, it was also recommended that occasionally and especially before storing the bike for winter one would shoot some WD40 through those holes to prevent rusting. My 750 Special still has the original mufflers with no rust. Meanwhile my 78 XS1100 which I got in 1988, already had both mufflers rusting and the PO had used hose clamps to hold in place tin cans to cover the rust holes on the bottom, But the holes you describe sound like the PO wanted it to sound like a Harley. Perhaps you could use your wielding skills to rebuild the backs, your lucky to have serviceable originals to work with. I have since replace the rusted ones on the XS1100 with a set from a Moto Guzzi California, they mounted up easily, but I had the assistance from a muffler shop to make adapters for the mufflers to fit into the headers. Sounds good just a bit louder than stock but the noise is acceptable, the mufflers are longer though and extend a bit past the turn signals in the rear.

[Ranger_xs1100]

I have zero welding skills so instead, I found this pack of 4 at Home Depot for about $2.00.... I can't remember if I used a high temp sealant or JB Weld under the washer before pop riveting it in place to cover the holes. It was an inexpensive, quick, easy, and effective solution. I also think it is a good idea to paint the washer. In my case I painted it black. It not only quieted, but also restored the power loss.

[Radioguylogs]

I had a set of XS750 pipes that a PO had drilled about 6 holes 1/4" diameter in a circular pattern. Maybe the PO wanted a louder sound or maybe they thought the performance would be improved. It made an awful whistling sound.

I tapped the holes and installed black allen head screws with a bit of Locktite. That fixed it.

[Solonys]

Thanks for the suggestions everyone! The holes in question are literally 1/2 inch each, so I think I'm going to attempt to cover them with Ranger's conduit washer, we will see where that gets me

[JonnyO]

I have zero welding skills so instead, I found this pack of 4 at Home Depot for about $2.00.... I can't remember if I used a high temp sealant or JB Weld under the washer before pop riveting it in place to cover the holes. It was an inexpensive, quick, easy, and effective solution. I also think it is a good idea to paint the washer. In my case I painted it black. It not only quieted, but also restored the power loss.

That's just brilliant!

[oldyam80sg]

Most people like myself removed the stock pipes long time ago and put aftermarket systems. I still have my 4 into 1 Kerker that I bought around 1986.

[Solonys]

So I finally got around to plugging the holes, and Ranger's idea worked a treat! Now I have noises I can actually hear that I have to fix, specifically something that sounds like a chain being dragged across the ground, so that's exciting, as well as re-syncing the carbs and idle adjustments.

Thanks for the help guys/gals!

[DiverRay]

GREAT! glad it helped. For the "chain noise", search on the ACCT, automatic cam chain ten. in the modification section of the forums. You can use the ACCT of a newer Yamaha and no longer have to worry that the chain may slip and crash valves to pistons. The OEM ten. on our bikes are known to fail, so it's a "must do" in my book.

[Ranger_xs1100]

So I finally got around to plugging the holes, and Ranger's idea worked a treat! Now I have noises I can actually hear that I have to fix, specifically something that sounds like a chain being dragged across the ground, so that's exciting, as well as re-syncing the carbs and idle adjustments.

Thanks for the help guys/gals!

Always glad to help!

[Solonys]

GREAT! glad it helped. For the "chain noise", search on the ACCT, automatic cam chain ten. in the modification section of the forums. You can use the ACCT of a newer Yamaha and no longer have to worry that the chain may slip and crash valves to pistons. The OEM ten. on our bikes are known to fail, so it's a "must do" in my book.

The ACCT was one of the first things I did when I got the bike along with rebuilding the brake calipers, replacing the fuse block, cleaning electrical connectors (which I think I need to do again, because the Tach is bouncing), etc., so I'm not entirely convinced it is cam chain noise yet, but thanks for the advice!

[DiverRay]

You may be hearing a little valve noise as well. That is a GOOD thing! No valve noise, no clearance, burned valves. Valve lash will get smaller as you drive, not bigger like a lot of engines. I always set mine at the top end of clearance, and they usually go for about 12-15K miles before needing adjustment again.

[cajun31]

my tach bounces on all of my xs11's. they are old and so is the tach. I don't worry about it because the speedometers work fine and is usually what I am watching.