75 Commando Muffler Dilema

I have a 1975 Commando MKIII , original unrestored , 1,800 miles on it in the John Player paint scheme in really nice condition.
It has the original black cap / bean can mufflers on it , and while up on the lift the other day noticed some rust holes in the bottom of the mufflers, right past the transition from head pipe to the muffler. After poking around in the holes it was apparent that it was worse that just a dime size hole.
So now comes the magic question. Are new black cap mufflers readily available in the US ? If I made the decision to change the entire exhaust to the pea shooter type like offered by commando specialties, would it negatively affect the value of the bike?
This would eliminate the balance tube, and I'm assuming re-jetting. Looking around it seems this is a common change out, but don't want to devalue the bike.
Thoughts ???

https://www.rgmnorton.co.uk/buy/bla...ht-through-baffle-system_1262.htm?sid=1310720
RGM have the regular and straight thru black caps. 80 GBP ea. good...junk ???
I'd probably try the straight thru if you keep the balance pipes. Finding aftermarket MKIII pipes to fit are hell....they are a 1 year only type system.
I don't see you worried about value. IMO an OEM unrestored MKIII is easily devalued a few grand for the OEM 1975 soft as butter cam...almost as bad as when I had to warranty a new/split chilled iron cam .

The original black cap mufflers are available from Andover Norton for £98, plus shipping. You may not consider that "readily available in the US", but ordering from them on-line is really simple, and they deliver rapidly. Buying from overseas no longer involves foreign currency money orders and waiting for delivery by boat, thank goodness. :lol: My recent order for a rear fender and some other bits from them arrived at my door five days after my on-line purchase.

They are also "available" from Old Britts here in the US, but they are out of stock at the moment, and with them kind of winding down the business, I don't know if they will be re-stocking the mufflers. You can always call and ask.

Ken

mrmach5 said:

So now comes the magic question. Are new black cap mufflers readily available in the US ?

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They should be available from any US Andover Norton parts supplier.
https://andover-norton.co.uk/en/shop-de ... black-cap-

mrmach5 said:

If I made the decision to change the entire exhaust to the pea shooter type like offered by commando specialties, would it negatively affect the value of the bike?

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Unlikely. Probably the opposite.

mrmach5 said:

This would eliminate the balance tube, and I'm assuming re-jetting.

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Yes, probably up to about 260 main jets (and perhaps raise the needles a notch?).
If you decide to fit peashooters, you wouldn't necessarily have to change the header pipes but you will need the peashooter mounting plates (3 each side) unless you make suitable adaptor plates.

This would eliminate the balance tube, and I'm assuming re-jetting.

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My experience with the MK2A is that no rejetting was needed just for losing the balance tube, but I had already gone to peashooters some years before and with these had to go to 260 mains from the 230 std mains but the needle position is unchanged as I have just fitted new slides and saw the setting is still by the book.

And my 2¢ is,,, my black caps rusted out and split about a hundred years ago and I replaced them with stock 74 downward 850 peashooters. They were baffled and almost as quiet as the "black caps". Now the bike has straight through peas from Emgo, I think, and both types fit fine with the original brackets though I had to drill two new holes per side on the plates the mufflers are actually bolted to because the header pipes are too short to accommodate the shorter "pea's". I'm guessing you're cringing at the thought of this because of "value" but you can always just purchase the plates that will work and stash the originals. At 1800 miles your cam is more than likely fine. And likely to stay that way for a long time with regular oil changes using a good 20w50 syn bike oil. My MK3's cam did not start to concern me until around 40000 miles until the need for frequent valve adjustment and filings showing up on the magnetic drain plug let me know a lobe was going and even at that the cam itself was not really wiped. I think it's unlikely you'll reach this point anyway 'cause, you know, accrued mileage erases "value" too. As far as pipes are concerned, my bike is running fine with the straight through "pea's" along with the original balanced pipes. Pretty sure my needles are at their mid groove location (been so long since I've had carbs apart) and jets are 240. Bike runs stellar with this set up.

I didn't realize your bike was so pristine. You should try to find correct original parts for it, when replacing anything on it . Just like your Hondas. There are plenty of hotrodded, modded ,upgraded ,whatever you call it,Norts out there ,(mine included!), but "theyareonlyoriginalonce"


here's a end of a "bean Can"
showing the correct markings and heres your bike and heres mine ( I do run a set of real MK111 muffs and I like them)

I have a K&N airfilter and peashooters with unbalanced pipes on my MarkIII. You can hang on to the original parts if you are worried about resale. Enjoy the better ride and easier maintenance.

baldy said:

I have a K&N airfilter and peashooters with unbalanced pipes on my MarkIII. You can hang on to the original parts if you are worried about resale. Enjoy the better ride and easier maintenance.

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I disagree, keep it original, with the original air cleaner and along with the correct Annular Discharge Silencers it is very quiet, and a joy. Plenty of loud Norton's out there. An air cleaner element can go unchanged for many miles, what else is there to do at less than 2000 miles?

No dilemma ,it's all good . "Protect the value of your investment" and get the new bean cans . My 76 runs like a quiet kitten . So unlike other Nortons in this Toronto area. We have a large rockers social scene here , your age and choice. 8)

There's only one person that can determine what the right approach is and that's the owner. What do you like the looks of? Unless someone else is willing to write the check for what they think is the right look then get what you want and to heck with what anybody else thinks or says.
As others have said black caps are available here in the US if that's the route that most appeals to you. I've had both and personally prefer the 750 style headers with pea shooters. Last year I purchased a full Viking set up and the fit and finish are spot on. They offer both pea shooter and black cap mufflers. It was my first time purchasing outside of the USA and went flawlessly. I was kept informed during the entire build process. Good people at Viking. I always thought that the black caps, while nice on an extended ride, sounded too much like a vacuum cleaner for my tastes. I guess that the juvenile anti-social part of me enjoys a bit of exhaust cackle when twisting the throttle. Good luck with whatever route you take.

jimbo said:

I disagree, keep it original, with the original air cleaner and along with the correct Annular Discharge Silencers it is very quiet, and a joy. Plenty of loud Norton's out there. An air cleaner element can go unchanged for many miles, what else is there to do at less than 2000 miles?

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+1
I was able to find a supplier of "bean can" silencers made of stainless steel for my project. The supplier is located in the UK. I think Armours list them too.
https://www.armoursltd.co.uk/
Err, apparently not, but there is a least one supplier out there. Please note that the Armour's sub-menu doesn't list the complete offering - you need to select the top level menu.

Cheers,

Knut

I had a Viking system on a T160 and it was top class. Rather expensive though, and I've heard some complain of long waiting times.

These look like a bargain... although you'd need to paint yer black caps black!

https://www.rgmnorton.co.uk/buy/black-c ... rettyPhoto

Fast Eddie said:

I had a Viking system on a T160 and it was top class. Rather expensive though, and I've heard some complain of long waiting times.

These look like a bargain... although you'd need to paint yer black caps black!

https://www.rgmnorton.co.uk/buy/black-c ... rettyPhoto

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might as well get pea shooters , the way those are made :shock:

the other ones they list might be a little quieter and look more like the originals.

https://www.rgmnorton.co.uk/buy/black-c ... rettyPhoto

Fast Eddie said:

I had a Viking system on a T160 and it was top class. Rather expensive though, and I've heard some complain of long waiting times.

These look like a bargain... although you'd need to paint yer black caps black!

https://www.rgmnorton.co.uk/buy/black-c ... rettyPhoto

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It was pricy but with the US dollar strong against the NZ currency it wasn't as bad expensive as in the past. The time wait can be long depending on were you are in the build cycle. I ordered mine just as they were ramping up for the headers. They arrived about 18 days after ordering. The silencers were their next build and they arrived two weeks after the headers. Not bad from a small operation. I ordered during the winter so the wait wasn't an issue