what size did you drill those out to? and is there a specific length away you should drill em?

Wake51 wrote on 05/04/12 at 01:59:31:


I bet you bought a HD muffler (Dyna) that somebody drilled or knocked out the baffle....and turned this into a straight through muffler.  The Dyna muffler is not very loud at all when it is not modified.

Is the baffle plate removable or does all the drilling take place while its mounted on the bike?

RanDaMan wrote on 06/27/12 at 12:25:07:

If you were referring to the stock muffler, yes you drill the rear while it is mounted on the bike.

renegade1 wrote on 06/04/12 at 11:55:26:


I did 4 x 1/2" holes.  There are four rivets in the rear baffle plate in the muffler (no idea why, they don't seem to hold anything...LOL)...I just drilled those 4 rivets out, then enlarged the holes to 1/2" each.  Drill through that rear baffle plate (which is something like 3/16" thick or so) and you're good....assuming we're talking about mod'ing the stock muffler here.  

That said, I got tired of that VW Beetle-ish "ping/whistle" and tried a Jardine exhaust.  Here's how I'd compare those three:

1) Stock muffler:  Just too quiet IMO...it sounded like I was riding a sewing machine.  

2) Stock muffer drilled: A bit louder, deeper tone (in physics terms, it's like tuning a subwoofer!), but still not what I'd call "loud", plus I still heard that VW Beetle-ish "ping" characteristic to it (which I understand comes from the internal baffles in the stock muffler).

3) Jardine:  Much louder than even the mod'ed stock muffler (just short of obnoxiously loud), not as deep as the mod'ed stock muffler, but has a mid-rangey, percussive "bark" to it, and is quite echo-ey loud under hard throttle.  This is what I have on mine now, and I quite like it.

Thanks my opinion.  

Dave

Yes, drilling the stock muffler is an easy mod.    As far as if it makes it loud enough that people hear you coming, I didn't think so myself...but that's me, YMMV!  Try it and see, nothing to lose by doing this mod...just check that you have about 3 turns counterclockwise (right guys?) on the fuel mix screw first. (Turn it all the way clockwise and count the turns so you'll know where you originally were, then check you can do 3 counterclockwise turns before it's too loose and might fall out.  Then follow the thread in the tech section about adjusting it after you've drilled the exhaust...essentially get it to where you have the highest revs at idle and it should be good, but read that thread so you know all the details. Search for "brass plug" and you'll find it. )

I got most of the metal shavings out with one of those "small magnet on a telescoping rod" thingamabob's, but I don't know of any ill effects if some metal shavings end up left in the muffler.

Cheers!
Dave

Here's a clip I posted a while back...this is the stock muffler with the 4 x 1/2" hole mod:  http://www.youtube.com/watch?v=FFeyIYBig80

Dave

Greg wrote on 06/27/12 at 14:32:28:



After listening to most of the sound clips I liked the sound of  greg's "Thrush glasspack p/n 24210" the most! I like the depth of the tone rather then higher pitch rev. This muffler would require re-jetting I assume?