Original mufflers? -How to tell?

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Johnnymac

Johnnymac

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Guys, I was recently at my local Gateway Nortons Owners club and one of the guys mentioned to me that it looked like I had the original mufflers on my commando. He said that original ones didn't have a straight edge at the tips. As you can see on mine if you zoom in, at the end of the muffler, the ends fold over a but resulting in a smaller exhaust hole. Do you know how to tell if they are indeed original mufflers? It would be insane if they were original as they look fantastic.

Original mufflers? -How to tell?
 
Originals have constant tapper not a step up from headers, ends welded over and internal baffle louvers that are crescent shaped for best sound effects over the straight cut or triangular cut stamped louvers. I only know this because a fella on BI and NOC list a decade ago wanted the original sound and checked out and photo'd every silencer available then. The main difference he said was the twittering sound on trailing throttle, if that makes sense to any of us nowadays.
 
Johnnymac said:
As you can see on mine if you zoom in, at the end of the muffler, the ends fold over a but resulting in a smaller exhaust hole. Do you know how to tell if they are indeed original mufflers?
Click to expand...


If they measure 1-1/8" diameter at the outlets then they might be 'Original Norton' peashooters, however, they are likely be the later 850 MkII type.
www.accessnorton.com

Pea shooter outlet ?

After many years its time to restore my old 74 850, gave the the guy making my new peashooters the old ones to copy but he said the old ones have an inch & 3/8 ID inlet & a 1'" 1/8 outlet & is sure that the inlet & outlet diameters are the same otherwise it might get somewhat constipated...
www.accessnorton.com www.accessnorton.com
 
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They're not rusty . Ah yes ,I remember now the lovely charming twittering sound on backoff throttle to gear down to stop. Distinctly Norton original enjoyment. Like a couple of birds set up shop in the mufflers and started chirping "Why are you slowing down ? ". I'd forgotten about the chirping after 5 sets over 35years. Thanks.
 
I can state with absolute certainty below photo is a '72 Commando roadster with original silencers. It's me in 1973 with a new '72 combat. The mufflers in your photo are not the same.

Original mufflers? -How to tell?
 
illf8ed said:
I can state with absolute certainty below photo is a '72 Commando roadster with original silencers. It's me in 1973 with a new '72 combat. The mufflers in your photo are not the same.

Original mufflers? -How to tell?
Click to expand...
Dave,
what do you see in his photo that looks different? my eye untrained eye doesn't spot anything obvious
 
Well, one lives and learns- I thought all 750s had the seamless type, only the 850s (and '73 750s) had the seam at the rear from cone to cone.
 
kevbo82 said:
illf8ed said:
I can state with absolute certainty below photo is a '72 Commando roadster with original silencers. It's me in 1973 with a new '72 combat. The mufflers in your photo are not the same.

Not in my photo, but in the subsequent posting showing the rear openning is not curved inward.
Click to expand...
Click to expand...
 
The originals off my 69/70S had welds around where the header attached, but the reverse cone attachment was smooth and the ends looked cut off. There was also a flat baffle inside about where the reverse cone started that blocked about 80% of the straight through pipe, so you couldn't put a bar through it. The Wassals I got as replacements have a sort of blatty sound at 55 and up. Don't sound as good as I remember the old ones.

Dave
69S
 
There were different varieties of peashooter mufflers back even when these things were new ??

I had a 73 Mk1 850 with its original tweety peashooters.
It had the little removeable 'mutes' in the end of the mufflers - as in the parts diagram - this was a little piece of parallel pipe, held in with a crosshead screw.
With it fitted, bike was surprisingly quiet (and legal ?), with it removed a bit more rorty.
The manual says it needs bigger jetting with the mutes removed.
When you looked through them, it had little triangular louvres in the walls, otherwise they looked to be empty and straight through.
Unfortunately, don't seem to have a photo of them.
 
Well I know that this is a terrible picture but I scoped the muffler and it does have triangular louvers.

Original mufflers? -How to tell?
 
Since everyone wants pics, here's my original S peashooters.

Original mufflers? -How to tell?


Original mufflers? -How to tell?


And here's the baffle that was in them.

Original mufflers? -How to tell?


Dave
69S
 
No seams on my Jan 1972 Combat. I have seen later '72 with seams but not 100% sure they are original. Could see straight thru them. Had the louvers. Also had hole for mutes in the ends.
 
Those are totally different to what was in the factory 850 peashooters.
The triangular louvres were only little things inside them, lots of them, only about 1/2" across.


Johnnymac said:
Well I know that this is a terrible picture but I scoped the muffler and it does have triangular louvers.

Original mufflers? -How to tell?
Click to expand...
 
I think it might be a little presumptuous to think that there is just one and only one type of peashooter muffler/pipe on all 72 Commando Roadsters/Combats. It almost looks like their are at least 3 different ones that are suppose to be original in the thread alone.
 
Rohan said:
Those are totally different to what was in the factory 850 peashooters.
The triangular louvres were only little things inside them, lots of them, only about 1/2" across.
Click to expand...


You mean like these?
Original mufflers? -How to tell?
 
concours said:
You mean like these?
Click to expand...

I don't remeber them in neat rows like that.
It was 30+ years ago.

What do the outside, and ends, of these mufflers look like ?
Do they have provision for the little mutes to be be into them - and the hole for the crosshead screw to retain them ?
 
Rohan said:
concours said:
You mean like these?
Click to expand...

I don't remeber them in neat rows like that.
It was 30+ years ago.

What do the outside, and ends, of these mufflers look like ?
Do they have provision for the little mutes to be be into them - and the hole for the crosshead screw to retain them ?
Click to expand...

No holes for the mute securing screw.
Original mufflers? -How to tell?


Original mufflers? -How to tell?


Original mufflers? -How to tell?
 
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