[Arizoni]

As some of you know I was looking for a used Harley muffler for my G5 and not having much luck.  Well, I lucked out!
One of our nice members offered me one so I now have it. (You guys are the best! )
I had to buy a clamp and a local Harley shop sold me a used one for $5.00.

As it turns out, the Harley silencer weighs 9 pounds less than the OEM silencer so in addition to the good looks the bike should go LOTS FASTER 

The silencer comes with a stout mounting bracket on the side and this bracket is designed to take 5/16" carriage bolts.  The kind with a short square under their rounded head.
Two 5/16 inch carriage bolts, two flat washers, two lock washers and two nuts later I was ready to go to work.

Being a nurdy engineer I measured the mounting locations used by the OEM silencer and fired up my Turbocad drafting program.
After giving it some thought I decided I wanted to use 2 brackets like the OEM's.  One to the passenger foot peg bracket and one to the forward bracket just behind the rear brake pivot.  Printing these drawings out at close to full size gave me something to compare my parts to so I could get the right offsets.
I used some 1/8" x 1" cold rolled steel from my local Ace Hardware store, a 3/8" drill bit, my hack saw, a vise and a file to cut and form the vertical bracket and I found a piece of 3/4" wide stock in my junk box to make the fore/aft bracket. (shown in photo 1 below)
I painted my new brackets with black Krylon BBQ paint that can take 1000 degrees F so that should last for a long time and protect the carbon steel brackets from rust.

Removing the old silencer isn't too hard but you should know that the heat shield locks into a tab on the exhaust pipe so it has to be removed to get the OEM silencer off.

The Harley muffler inlet is slightly larger than the RE's exhaust pipe so I had to make a sheet metal ring to fill the gap.  For this I used a piece of 1/32" thick aluminum I had laying around.  It is easily cut and formed and aluminum's melting temperature is over 1100 degrees F so it should be able to take the heat (I hope).
The stock for this ring should be about 1" wide and 5.340 long and trimmed so there is almost no end gap when it is tightly fitting the exhaust pipe.  The end gap will be a leak path so take your time in fitting it.

I had to modify the Harley clamp with my Dremel tool with a cut off wheel installed by cutting off part of a short leg to get it to clamp the new silencer tightly.
Beyond that, everything went as planned so the silencer is installed.

I will polish out the yellowed chrome on the exhaust pipe but I think I’ll have to find/make a heat shield to cover up that ugly heat shield retainer and its uglier aluminum paint shown in the picture below.
This silencer still has the factory baffles in it and stamped on the side it says its loudness is 80 Db, the same as the RE’s OEM silencer.
My first ride with the new silencer shows that there is no backfiring on decel but the seat of my pants says the acceleration torque is less than with the OEM silencer.
It still pulls pretty good but not as strongly as it did before the change.
A high speed run shows the bike will still hit an indicated 80mph but its working harder to do it.
I think the old aircraft length 3/8" drill bit is going to attack some of the Harleys internal baffles.

[Thumper]

After my Hitchcock's GoldStar silencer stress fractured in two places and welding was not an option, I pulled it off. My son had two HD mufflers like yours (Sportster??) just lying around from his project bike - and gave one to me. I also fabricated mounting brackets and ran it for about 18 months. It ran and sounded great. Same (Amal) carb settings as the old exhaust - so no fussing with needles and jets! After about 18 months, I finally broke down and bought another Goldstar style and installed it (that was about 5 months ago).
   
So, I guess we can say to the crowd - and yet another muffler option is to run a Hardly muffler on it!
   

[GSS]

Very nice! I did the same mod a couple of weeks ago on my C5. The OEM sounded fine but was one large, heavy, multicolored mosaic of blue and yellow chrome.  I put in a Silman short bottle silencer from Bulletwala.....great looks and sound, improved acceleration, but I was getting a bit concerned about the noise and the chrome was yellowing. So in went the Harley softail muffler with a heat shield....looks great....no discoloration, and the sound is almost as quiet at RE stock. I too noticed a slight drop in responsiveness, but will stick with it for now. Photos to follow once I get to a real computer.

GSS

[JVS]

Hey GSS,

The Silman short bottle, is it compatible with the UCE engines? i.e. EFI and all that? Does the ECU adjust to this silencer like the EFI silencers are designed to, for some backpressure? O_O

[JVS]

My bad. Arizoni, great job you have done. Is it over-the-top loud or decent enough? It says 80dB, isn't that less than the stock torpedo, which has indicated loudness of 90dB around the 2250 RPM mark?

[Arizoni]

I can't find data that says what the RE OEM silencer is but the EPA rule is 80db at a 50 foot distance.  California also has this 80db limit and the stock EFI Bullet meets that.

The Harley muffler I installed has the internal baffle and perforated tubes but no catalytic converter.  It sounds almost exactly like the stock Royal Enfield muffler.

Well, I should say 'it did sound like...." because I just drilled a 3/8" hole thru the plug that separates the front  from the rear.   This plug forces all of the exhaust to pass thru a lot of  1/8" diameter holes in the inlet pipe into the outer chamber.  The exhaust then must pass thru a lot of 1/8" diameter holes to get into the outlet pipe.

Now that it is drilled the idle noise is about the same as it was when I got it.  A twist of the wrist says the volume has increased by at least 10db.

It's too hot out there to ride it right now but I'll give it the usual Friday ride tomorrow and let you folks know what the new hole did to it.

[GSS]

Hey GSS,

The Silman short bottle, is it compatible with the UCE engines? i.e. EFI and all that? Does the ECU adjust to this silencer like the EFI silencers are designed to, for some backpressure? O_O

The Silman short bottle is not an open through and through muffler, so there is some back pressure and it is not as loud or blatty as some of the others.  I had a couple of loud backfires during hard deceleration for the first few days and then it all settled down to a muted rumble during hard deceleration.  The increase in power was definitely obvious, but I got a bit tired of the noise.

The Harley on the other hand is a really quiet muffler....sure isn't in line with the stereotype Harley racket....this one came with a catalytic converter as well as a nice heat shield.

Anyway, the Silman works great with the UCE-ECU.

[JVS]

Thanks for the replies, guys. I shall stick with the EFI silencer at this stage, happy with it. Not too loud, not too quiet.

[gremlin]

Wait for it ......   When I first modified mine with a Harley muffler I noticed an immediate drop in responsiveness, and MPG.  two tanks of fuel later and my mileage was back to normal and *I* think it is breathing a touch easier on the 65 mph commute.

[gremlin]

Mine also barks more on acceleration, and, I get an occasional crackle on the termination from acceleration -to- deceleration. (of course, that post-acceleration noise might just be the CAT clearing itself.)

[GSS]

Comparison of OEM, Silman short bottle (also sometimes referred to as the Ludhiana silencer, Punjab silencer, Electra/500cc silencer) and Harley photos with mount locations.  The front bracket from the OEM and a slightly bent rear bracket from the short bottle worked beautifully with the Harley Softail.

[tooseevee]

The Harley on the other hand is a really quiet muffler....sure isn't in line with the stereotype Harley racket....this one came with a catalytic converter as well as a nice heat shield.

             Those days are LONG gone. Stock harley mufflers are just as quiet as any others now & have been for years. harley is just as strangled & nannied to death by regulations as any other motorcycles worldwide. If the harley you hear is irritating by your standards, it has been modified by somebody (maybe ME) the same as we (I) modify stock Royal Enfields. 

[BrashRooster]

Pretty sweet! I personally dig my discolored silencer. This one is really coming out with the blues and violetish colors rather nicely. Most of the brown and yellow is gone not all but most. My header only has very light discoloration and it is confined to a small area.  I think it is cool that you have what you want on your bike though!

[Arizoni]

Wait for it ......   When I first modified mine with a Harley muffler I noticed an immediate drop in responsiveness, and MPG.  two tanks of fuel later and my mileage was back to normal and *I* think it is breathing a touch easier on the 65 mph commute.

I'm impatient I guess.
I used my 3/8" aircraft length drill to poke a hole thru the baffle that separates the front and rear tubes.

Today on my ride I found that the old torque and acceleration was "almost" back to the pre-swap condition.
Still no sign of any backfiring on deceleration, even when I shift down a few gears to try to force a backfire. 

It still could use just a 'bit' more 'opening it up' so I'll look around and see if I can find a 1/4 or 5/16" diameter drill.
These "aircraft length" drill bits are about 12" long and not every store carries them.

Adding the 3/8" hole to the baffle did not add much noise to the sound at idle speed.

When cruising along at a constant speed of 45-50 mph where the old silencer was almost silent I can now hear the purr of the exhaust.  Far from loud but definitely more than the OEM.
  During acceleration however the loudness increased probably 20-25 percent.
Still not really loud but definitely louder than the OEM silencer while coming up to speed. 

[indyogb]

Anybody ever tried one of the new Triumph mufflers?  My B5's bazooka is starting to turn purple, so I think a change may be in order this fall.  I do like the stock quiet sound, but just not the length and discoloration.  I may look on eBay to see if I can score a cheap one and try it.

Alternatively, I wonder how difficult it would be to get one of the EFI or stock silencers ceramic coated.  Is it even possible to disasemble/reassemble the stock muffler?  Gotta be pretty difficult short of hacking it apart and welding it together again.  I don't know, I'm still brainstorming at the moment (always dangerous).