Time to bury the Amals?

everyone seems to really like the new Premiers

question: are the slides the same metallurgy as the bodies?

the "old" Amals used potmetal and the slides would rattle in the bores and wear, quickly creating unwanted air leaks into the manifolds and causing countless young Nortoneers unlimited global cursing

After 20 years with a single Mikuni 34 on my 850 which I was very happy with I happened to ride a friend's Commando with a twin carb setup and was amazed at how much stronger it was than mine above 4500rpm

the new Amal Premiers were not quite out yet and so I bought one of the first twin PWK carbs that Jim Schmidt sells, and for a considerably less amount of money than new Premiers.

After over three years now I still quite happy with the PWK flat slides, bike starts second kick after drawing in the fuel on the first kick, idle like a rock, and flow strongly right up to red line.

1Up, changing bikes and attributing different performance to the twin carbs might be a bit dubious. There are many things which affect performance at various parts of the rev range. With my own bike, I do everything I can to emphasise the midrange characteristics.

good point, acotel

seat of the pants riding impressions going from a single Mikuni to a twin carb set is just that, how it feels

however, other than Hobot, I don't think anyone seriously believes that a single Mikuni in a Commando can flow enough air above say 4500rpm than a good twin carb setup

IF that was the case, then everyone racing Commandos would be using single carbs, and they are not

JimC said:

I, too, like the vintage aspect. It just isn't too practical for some Norton owners. For more than a few, their Commandos are daily riders. Ethanol spiked gas has rendered the fiberglass tank useless. The original front disc brake on the 72 and up Commandos was very poor, to be generous. The sizing of the master cylinder bore was way off the mark. Pogoing off a dropped brake pedal wasn't fun. Two piece rear axles should have never been made. The many upgrades and fixes discussed here are pretty desirable if you want to turn your Commando into a reliable, safe, daily rider.
Stock vintage bikes remind me of the old joke about Harleys: 98% of the Harleys sold are still on the road, the other 2% made it home.

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Okay. I have two Amals on my Norton that most people would not have ever thought of using. They had some chips in the body and they were dirty and sitting in a junk box with dried up gas in them for decades. I took them apart and cleaned them up the best I could and put them back together with all the original parts, even the old gaskets. In fact the whole bike is all old parts except for the rear shocks and four Hastings compression rings. The rest is all old used parts with some new old replacement valves and guides.

I put it together from a basket of parts and it started first kick, warmed up and idled and ran great. I never had to touch the idle or mixture again. The magneto has not been rewound and does not have a new capacitor or points or bearings or gaskets and it starts the bike in one kick when it is cold and when it is piping hot and works in the rain.

I have been running drum brakes for the last few decades and before that I had stood a stock 850 Commando up on it's front wheel. I have never been stranded by a stock Norton, ever. I have never had to have one trucked home. When an ignition switch went bad, I shorted the wiring out with beer can metal and rode home. When the float bowl fell of the carb I found a piece of coat hanger and wired it back together through the boat holes and made it where i was going.

If you are getting into trouble in traffic it is not your vehicles problem, it is your driving style. In the 50s and 60s people in the largest cities in the world rode British bikes in traffic, and they also rode them across continents. If you can not do it today, just as with your problems with traffic, it is not the bike it is you.

Any time I was ever stranded it was my doing, running out of gas or making a mistake as a mechanic or forgetting something, it was never the bikes fault. And any time I ever got into trouble with traffic that was all my fault too.

It is ridiculous that you guys blame machinery that did the job for many decades and proved itself. Tear the Norton badge of the tanks of your bikes and paint the Visa logo there. Brittany Spears could take the place of any one of you, because she can throw her old shit in the garbage, pick up a Visa card and her smart phone and buy a pile of new shit then pay someone to put it on the bike for her so she can pose around Hollywood.

You know what happens to old motorcycles that have been owned for decades by people who don't really care for motorcycles because they are just cheap transport,they end up on eBay in parts with 99c start bids.

I rebuilt the Amals on the Mk2a,the bowls were so warped that even with a new gasket and the screws nipped up there was a 0.010" gap between gasket and body.
Its been a while since I had to use glass and sand paper.
I am onto the rear RGM Isolastic right now,both were shot,next is to strip the transmission and will probably strip the engine also,I have never heard it run.
Hopefully it doesn't have bits of coat hanger wire in place of the con rod bolts.

It had a 22T front sprocket which seems a little over the top in getting revs down.

Not on topic, but since you mention the 22 tooth sprocket, funny thing with the Commando is you need to keep the revs up in order to stay out of the vibration zone.
Every other motorcycle I have ridden is the opposite, gear it up, the revs drop at any given speed and so does the vibration.
Not that the 22 tooth is a bad idea, but you will have to go a bit faster than me (21tooth) in each gear before things will smoothen out. If your bike is like mine, once it is up in the smooth rpm band it will run right to the top and stay very smooth all the way. Mk3 850.

Glen

Staying near the topic seems to be the norm.
I have never ridden an 850 and elected to not start this 'restored US import after going over it,the story being it was done by a well known 'pin striper from New York (iirc) in the mid 2000's.
Its a nice bike but seems to have been neglected since then.
The rear Isolastic was a snap to install compared to the front,the phone rang not long after and I fly to another project next week so the Norton experience will be on hold again.
I better order a new front sprocket,21 T :?:

It depends on the type of riding you do. If you are almost always on highways, your speed will be sufficient to stay out of the vibe zone, even with the 22 tooth. If you also ride on slower roads with 45-50 mph traffic, then I think the 21is a better choice. It will give you a little more acceleration as well, which is always nice.
Top end is still plenty high with the 21 tooth.
Glen

Excellent,I will order a 21T.

i went for 23 thinking it would be better only having 4 speed. Takes a bit of clutch and is very tall but I'm happy enough
Shame changing sprockets is so involved but the vibration does have a positive effect for the pillion. Maybe that has something to do with the marques popularity?

So the update on the Amals.... I put in new Premieres and the damn thing runs great. Must have been the wear in the barrels because now, it starts 1st/2nd kick, plugs look good (still an oil issue with right side valve guide) and it sounds awesome on the throttle.

Wish I'd replaced them in the first place but its all about false economies with me; bought the Norton to ride to work and save gas ~ HA!

BC

Jed said:

i went for 23 thinking it would be better only having 4 speed. Takes a bit of clutch and is very tall but I'm happy enough
Shame changing sprockets is so involved but the vibration does have a positive effect for the pillion. Maybe that has something to do with the marques popularity?

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I'm quite sure my wife of 20 years was "influenced" by the Norton rides when we were dating.

I don't know the difference between a 34mm Mk2 Amal and a 34mm Mikuni. In both of them the idle circuits are probably much the same including the air jets and pilots, as are the main jets. All of those are pretty irrelevant to normal riding. The area of throttle opening from 1/4 to 3/4 is where most riders normally have the throttle when riding. In this respect the Mikuni is probably marginally better because, particularly in the early days there was a much larger range of needles available so you could get the tuning finer. For most riders, it doesn't matter if the bike is jetted slightly rich - they would never recognise the difference in performance. One thing which is very important on any bike is that the carburettors must be insulated from vibration or the fuel level becomes higher in the bowl and richens the mixture across the whole rev range. All it takes is for a bell mouth to tap against almost anything in it's surroundings and you can get frothing. I would never rigidly mount a carburettor, particularly on a twin. My Amals have rubber mounts which I bought from Mick Hemmings years ago. The type of rubber is important - it must suit the fuel you use or you can get cracking. The second pair of mounts I bought were I think intended for use with methanol, and have been on the bike for years without a crack appearing. The first two cracked within 12 months.
I use bellmouths about 4 inches long, they are smart looking aftermarket items and I doubt they really do anything for the performance. As long as the inlet length is somewhere near right, the exhaust system configuration and cam timing are much more important.
P.S. I've just measured the my inlet tract length - it is about 9 inches from the end of the bell mouth to the centre if the inlet valve.
With a near standard commando on the street, you might be better with an air box surrounding the carbs with the filter up under the seat. It could seal much closer to the head, where the inlet tract is rigid. That air filter on the standard bike holds the ends of the bellmouths fairly rigidly, and I think the filter is also rigidly mounted.

Alan.....your inlet tract is way to short....

10.5 to the valve would be OK, but 10.5 to the head face would be better!