Norton Commando sound with original fitment silencers. 

It has the Combat head so compression is 10:1. it is also gas flowed by Norman White and I run Black Diamond Valves that I cut the seats with more than one angle for better flow. The cam is PW3. I know from my own experience though that the main contributor to how crisp its sounds, is the fact I am running the original silencers as fitted by Norton up to 73. Back in the 70s I had to replace one side, and got an original from Gus Kuhn who said, "You will never get another one of these, this is the last one", and sure enough, when I had to replace the other side I had to get one of the pattern ones that everybody uses these days. One day down the pub, a fella who was about to sell his Commando was quite happy for me to swap my newish pattern silencer for one of his originals along with buying him a beer. The difference in sound quality on the way home showed just how muffled the pattern ones are, it sounded like it was running on two cylinders again where as before it sounded like it was running on one and a half.

Yes, at least compared to all the pattern Peashooters I have ever seen, and that includes the later ones that Norton themselves produced with "Norton" embossed on the side. If you look at my original ones from about 1:30, you will see they are quite cavernous inside and follow more the megaphone shape of the externals. The main thing I notice compared to pattern ones I also own, is the outlet, my pattern ones, that maybe Toga, have a straight tube that is an inch or two long and that doesn't even follow the shape of the rest of the internals, whereas these genuine ones flow right to the end were they curve into that final constriction which is about half an inch. My first Commando was the MKV 750 you have, that went very well from standard, even better once I had Dudley Ward flow the head and put a 4S cam in it. It out accelerated the Kawasaki GPZ 750 when they came out at the start of the 80s.

Yes they were, sorry. You may be getting confused with earlier peashooters such as those fitted to the 1969 and 70s models such as the S type, which indeed had no seam. If you look up the Norton adverts with the Norton Girls, such as the one entitled "Temptation", you can clearly see that they have that welded seam around the larger end cone.

​@@petercharlton515Sorry, if you're talking about your 72 Combat mufflers, new peashooters supplied with Combats were seamless. One year later, early-mid '73, seamless were no longer available until almost 1980. And those peashooters you're showing have no sound I'm familiar with. How do I know? I own 4 Combats and still have the rusted burnt out original peashooters that were supplied on two of them. They didn't last that long that you would still have a pair. There were several peashooter suppliers but those being shown are not Combat originals. You're guessing. Nice try though.

@@NortonCombat-ib3xw Back in the 70s, I had the 1973 MKV 750, they were exactly the same as these I have fitted to my present Combat in this video, now maybe I am mistaken and the 72 MKIV had seamless, but these I have are still original Norton fitment, I had them on my MKV then in 78 I needed a new one, Gus Kuhns said, "this is the last one, you won't find another one like this", and sure enough, some months later I needed another one, and had to buy a pattern Toga which was much quieter and more restrictive. Having said that, I think you are in error as all the roadtests and adverts for the MKIV show these silencers with the seam at the last cone, here is a Cycle World road test from 72, you can see the seam at the end cone, have a look at the Norton adverts of the time. As far as I am aware, it was the earlier peashooters that were completely seamless and they had a little hole at the end for optional mufflers to quieten it a bit. As for my still having a pair, it took me 25 years going around autojumbles and looking inside for genuine Norton ones, if they cannot possibly be genuine after all this time, this would suggest that there is an aftermarket supplier who makes the internals exactly the same. Now I have never seen these and would love a pair of new ones as the ones on my bike now are rather tatty and have scrapes all along the bottom of one, please let me know if you ever encounter them. magazine.cycleworld.com/article/1972/5/1/norton-commando

Further to my last, are you guys who do not think these are Commando Peashooters in the States? I wonder if we got the loud ones here in the UK and yours had to be quieter for legislation?