[Chasfield]

I got my 500 Classic a bit over gassed the other day while starting from cold. It back-fired into the exhaust down pipe, then about a second later there was a secondary detonation from somewhere in the labyrinth of baffling that fills the stock, Zeppelin-like silencer. Maybe there was actually only one bang and it just got lost somewhere on the way out!

It is amazing that RE could make an exhaust system with so large a volume that is so restrictive. If you look in the front end of it you see that the first stage of baffling is right up against the exhaust entry point. Would not leaving the first foot clear as an expansion chamber have resulted in much better breathing and maintained regulation friendly decibel levels?

[PhilJ]

If you like it to be somewhat quite but have a good thumper rumble try to find a '60s BSA muffler. I got a use one for 20 bucks and is perfect for me. You 'll need to get a muffler shop to build an adaptor. Very simple and quick cost me $5. I love it. Gives much better sound and more torque.

[meilaushi]

Actually, in the end of the head-pipe is a restriction that reduces the diameter of the head pipe before it enters the silencer to about the size of a medium sized thumb or a bit smaller.  That's a good bit of restriction.  It is supposed, according to what I've been given to understand, to be part of a kind of catalytic converter (EPA stuff).  If you want a nice deep and proper "Thump" and to allow the engine to breathe out much more easily, you might want to get either the Indian or the English made original 'shortie' silencer and headpipe (the present OEM headpipe won't fit either silencer).  These units are obtainable from Classic Motor Works in the U.S., or your RE dealer can obtain (and install) one for you.  I think also Watsonian in GB handles these as well,  Over here in "the colonies" (US) they run between c. 180 - 280 USD Indian made or British made for the headpipe and silencer without installation.
L & L in Hubbard Ohio got my set and installed it for me and it made a real difference with regard to power as well as giving the bike a really nice, pleasing, but not too loud 'Thump'... i.e., the neighbors won't want to kill you when you ride by.
Check out (If you're in the States) CMW's on-line catalog, or, if in the U.K., Watsonian's.

[Chasfield]

PhilJ:
That BSA item sounds like a good choice. I have a modern shorty silencer in the shed but it is a bit loud. Tried one of those 4 inch add-on baffles off ebay in it, which gave a flat hitting-a-tea tray with a hammer sound and poor starting. Cut baffle in half and drilled extra holes in it - too loud again but ran quite nicely. I went back to the stock silencer.

meilaushi:
I had read about the catalytic orifice thing that blocks the down pipe. Luckily my bike had a straight through regular front pipe installed with the noisy silencer mentioned above, so that source of blockage has already been solved. I will have a look around for alternative silencers bearing in mind the advice you guys have given.

Thanks.

[meilaushi]

Sounds like PhilJ's suggestion of the Beeser silencer's a good one, and certainly was less expensive than going for new.  As he mentioned, the big thing there would be apparently manufacturing the proper attach points.  But then Matt had to make a different attachment to put my Indian headpipe/silencer from CMW on, as the connector under the footpeg was off by too much to fit on the bolt there.  So the Indian ones don't come immediately attachable necessarily either.

[PhilJ]

I attached to the original points. I used strap metal on both points. The front is bent and slotted. The rear is just straight piece of strapping mounted to the muffler at it's mounting point with a 8mm bolt. I'll attach a file, it's way to big but if you'll open it in another tab or window you'll see it nicely.

[c1skout]

  I drilled 6 or 8 3/8" holes in both the input and ouput sides of my stock muffler. It made it slightly louder than it was and I had to re-jet to suit... so it must flow better too. I tried a factory take-off from a large Harley for a while but didn't bother jetting for it. That one increased my mid-range power but kinda fell on its face on the top end. It would have been nice to jet for that one and try it some more but I didn't like the sound. My brother said it sounded like a lawn mower.

[Leonard]

I thought some of you might like to see the inside of the stock muffler.  I cut about 12" out of mine.  It doesn't sound too bad, not as loud as the India shorty that CMW sells but much less restrictive that stock.  You must re-jet if you make any kind of modification to stock or put on a new one.
Propably the best thing one could do is remove that catalytic converter from the end of the header pipe.  But remember re-jet and do plug chops.

[Leonard]

More of stock muffler

[Chasfield]

Leonard

Those pictures are really interesting, Thank you for posting them up. They confirm my feeling that the stock silencer could have been pretty efficient given its volume - and it is not stuffed with saw dust as I had first suspected. I am sure those three perforated baffle units could be quite free flowing if the circular bulkheads had been arranged with more thought.

[meilaushi]

That's a neat approach, but I wonder if all the work involved is worth it as compared to just obtaining and installing the shorty early style muffler?  I put the latter on my bike (the one made in India that CMW sells) and engine breathing is now great, and the sound is a million times better than the 'zeppelin'.  It's a nice, not loud, but deep throaty thump "the way a thump should be."
The more expensive English shorty I'd imagine would be equally good. 

[Leonard]

I agree with meilaushi, you can drill holes in the stock pipe all day and it will still be long and ,IMO ugly.  The shorter pipes just look better.

[bob bezin]

the british one is wayyyy better ! the chrome still has not peeled (like the last two indian ones], and the removable baffel. is a nice extra. I went to the s&s 50th in lacrosse wi. with the baffel out .why? just picture several thousand harleys.the bike was photographed from a moving car while going down the street. but i now run it with the baffel in. sounds great.

[meilaushi]

Bob, thanks for the info on the Brit shorty...  If my Indian jobber begins to go south, I'll spring for that one.  The Indian doesn't appear to have a removable baffle, but I like the sound of it, so I figure it's a keeper (benefits the wallet and ears) for the time being at least.  ... I can understand removing the baffle in the Englischer in order to go among them Harleys--feller has to do something to protect himself and stand out amid all the potato racket. 

[redcat]

Does removing or replacing the baffle cause a need for any carb adjustment?