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Single to Dual Amal Setup

Discussion in 'Norton Commando Motorcycles (Classic)' started by Tornado, May 22, 2019.

  1. MexicoMike

    MexicoMike

    Joined:
    Jan 31, 2010
    Just want to add to one item that has been mentioned that I learned when I started making up my own cables - you can't solder to stainless steel without flux designed for that purpose! So if you try to solder a cable using your rosin-core electrical solder and you get PO'd because of your lack of ability to do so, there's a good chance you are trying to solder to a SS cable! ;) (Rosin-core solder is fine for the job IF you are using "standard" cable.)

    I probably spent an hour of "WTF?" the first time I ran into SS cable - not realizing that's what it was. ;)
     
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  2. concours

    concours VIP MEMBER

    Joined:
    Dec 29, 2011
    Has this been mentioned yet? Item 15? 026476 Throttle stop, large, No. 45
    B42ABEA1-29BC-45C6-A665-E522070045A7.png
    8D8DCBC4-3BE0-4A3A-83E9-1A2EA7BC5FE0.png
     
    Last edited: May 26, 2019
  3. L.A.B.

    L.A.B. Moderator VIP MEMBER

    Joined:
    Nov 20, 2004

    That's part of the standard action twist grip. The (correct for Mk2) Amal Quick action twist grip (screw heads on top) shown in Tornado's photo doesn't have it.


    https://www.oldbritts.com/1973_g21.html


    https://andover-norton.co.uk/en/shop-drawing/196/controls-and-control-cables#
    Standard Edit: (AN's standard '8A' twist grip shown below is also Amal (screw heads on top, not the original Commando 06-2032 Doherty item with screw heads below):
    https://andover-norton.co.uk/en/shop-details/20576/single-cable-twist-grip-7-8-bars-amal-type-16-417
    Quick action 06-4600:
    https://andover-norton.co.uk/en/sho...tgrip-7-8-bars-amal-type-364-replica-06-4600-

    Doherty 06-2032:
    https://www.ebay.co.uk/itm/06-2032-...RIUMPH-NORTON-BSA-AJS-VELOCETTE-/273806758682
     
    Last edited: May 26, 2019
  4. montelatici

    montelatici

    Joined:
    Aug 26, 2009


    Once we installed the Wassells, the bike started right up with no float tickling and just some choke and the idling was perfect with quick recovery to a steady idle after revving. The Wassels are also about 100 bucks cheaper than the Amal Premium they are selling these days and have all the same improvements in materials and functionality.
     
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  5. Tornado

    Tornado VIP MEMBER

    Joined:
    Dec 5, 2017
    Good to know the Wassels getting it done for the 850. I assume standard jets and slider? Will be going to these one day I suspect, once I decide if dual carbs are right for me.
    My original amals have some slider wear, one more slop than other. Will swap in a pair of the Wassel Evolution anodized sliders to improve things...only $22 each from Eurojamb.com.
     
  6. MexicoMike

    MexicoMike

    Joined:
    Jan 31, 2010
    Nice video! FWIW, the Amal Premier's have the same "problem" with the fuel inlets - a single inlet for each carb is supplied rather than the OEM-type fittings. So, as with the Wassels, if you are replacing an old set of Amals with a new set of premiers, you have to reuse the original fuel feed fittings. If you are replacing a single carb with a pair, you will have to buy the appropriate fittings separately as well.

    Tornado - if the carb bodies are worn, you might not get the improvement you are hoping for with new slides; a pair of the Wassels (or Premiers) would remove any possibility of air leakage between slide and body... ;)

    Not saying new slides won't perhaps do the job, but I have had a good bit of experience trying to save some money and then end up buying the thing I was hoping NOT to buy PLUS having bought the thing I was hoping would correct the problem but didn't... :( Just trying to save you the cost of buying a pair of slides and THEN buying a new set of carbs! :)
     
    Last edited: May 27, 2019
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  7. Tornado

    Tornado VIP MEMBER

    Joined:
    Dec 5, 2017
    Yes, fully understand MexMike. The sloppiest fitting slide is on the carb I've been running as a single for past year with pretty decent performance. Other body had some clogged jet or fuel pick up passage issues, now resolved (hopefully). So I think fresh sliders may give some benefit/life extension which which is what I'm after for now.
     
  8. acotrel

    acotrel

    Joined:
    Jun 30, 2012
    Wouldn't you guys do better if you fitted rubberised mounts for the carbs and used spigot mount carbs instead of flanged ? Vibration can cause flooding which richens the mixture making the motor sluggish. I bought my flexible mounts from Mick Hemmings.
     
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  9. concours

    concours VIP MEMBER

    Joined:
    Dec 29, 2011
    Seems to work ok though...
    80182B0F-D232-4995-AE8A-6F4C777401EF.png
     
  10. Tornado

    Tornado VIP MEMBER

    Joined:
    Dec 5, 2017
    Can't see how eliminating smaller vibes at carb mount will do much as the whole engine is jumping up and down in the is mounts. Surprising these carbs seem so vibration tolerant with regard to fueling. I guess the design keeps volume of fuel in the bowl contained there no matter how badly the float gets bounced around. But the slide/bore wear does appear to be a side effect of vibration.
     
  11. montelatici

    montelatici

    Joined:
    Aug 26, 2009
    Unless you have solid mounted the engine for some reason, I don't think that rubberized mounts are at all useful on a Commando.
     
  12. o0norton0o

    o0norton0o VIP MEMBER

    Joined:
    Apr 27, 2015
    Slide body wear is probably not from the effect of the engine vibration due to the pistons going up and down, as much as the vibration caused by the force of the engine vacuum pulling and releasing the slide body against the carb body. The needle is doing the same thing inside of the needle jet which causes the needle jet to wear too.

    My dual amals have been good for a long time. I wonder if the slide body wear (which makes the mixture leaner) and the needle jet wear (which makes the mixture richer) have somehow canceled each other out to some degree.
     
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  13. montelatici

    montelatici

    Joined:
    Aug 26, 2009
    Yes everything as standard from the factory. I had installed 260 mains and stock was 270 which the Wassells came with. The surface of the Wassell slides, may not be compatible with the old Amal slide lining. I suspect that these Wassell slides might wear down the aluminum of a standard Amal quickly.
     
  14. Tornado

    Tornado VIP MEMBER

    Joined:
    Dec 5, 2017
    Yes, that bore wear may be of concern with hardened slides. But, if I can get another few seasons use out of the bodies then the $44 invested in the slides will have been worth it. I've got a buddy with 4 commandos running original amals. He is not one to molly-coddle his bikes...pushes them hard, does bare minimum to keep them running. They have 2-3x the miles on my bike (now at 12k miles) and he has no plans to replace amals. That is encouraging to my situation. I'm much more preventative work oriented.

    Sometimes I feel I fret too much on all these things....just need to relax, don't worry and go for a ride :)
     
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  15. worntorn

    worntorn

    Joined:
    Dec 22, 2006
    My MK3 has 26,000 on the original carbs.
    The slides are still OK and it runs well, nice steady idle.
    One of these days I'll fit Premieres but at present there is no need.
    A lot of the issues with worn Concentrics are just the needle jets being worn, so the whole carb gets tossed.
    I changed the needle jets and needles a couple of years ago when the bike started to run rich.
    Back to 55 mpg Imperial now.

    Glen
     
  16. Tornado

    Tornado VIP MEMBER

    Joined:
    Dec 5, 2017
    UPDATE: Bike on a high carb loading diet!

    Got the trimmed upper throttle cable yesterday and set about completing the dualiie config today. Used Bushmans guide to perform basic synchronizing and slide stops adjusted. Bike started first kick. Took a fair amount of tweaking throttle stop and pilot mixture screws to get it idling somewhere near what it needs. Right side makes a sort higher pitched chirping out the muted peashooter while left side sounds more like it did with single carb...pop pop pop...

    After few turns around the block found it tended to dip idle just beginning throttle roll on, reminiscent of what I saw when the needle jet needed replacing on the single, but these are new jets & needle and this was much milder and not threatening a stall. Soon learned this affect could be eliminated by very fine slide stop adjustments left or right side until both were more in syn. So guess the dip was more about one side being at a different airflow than other.

    Went out for a rip up the mountain. WOW, power on demand! Significantly more than the single and at 4500+ when the cams switch on, I'd swear she pulls harder than my modern T100 Bonneville. At top of mountain I hoped off to check things and found an alarming amount of oil coming down front of engine and the ham can front plate well coated. Closer inspected seemed to show intake rocker cover as the culprit. High tailed it home carefully watching pressure gauge but all was fine. Oil level at home is right where it should be. Letting things cool down now before clean up and diagnosis.

    Overall I'm impressed but I'm sure it needs more dialing and some experienced hands to make it right.
     
    Last edited: Jun 1, 2019
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  17. acotrel

    acotrel

    Joined:
    Jun 30, 2012

    The Commando engine is not solidly mounted, however it still vibrates within it's rubber mounts and if the carbs are solidly mounted to the engine, the floats must experience that vibration. If the fuel level rises because of the floats bouncing, the mixture right across the full range of throttle openings would become richer. It would not matter at full throttle, but at mid openings acceleration rate would become slightly sluggish. With a rigidly mounted motor, it is normal to use a balance factor which gives smooth running at high revs. With a Commando the crank balance factor is usually much lower, so you get more vibes at high revs. Because of the rubber mounts, you don't feel it, but the carbs still do. It might not matter for normal road use, but it depends on how finely you jet your carbs.
     
  18. Fast Eddie

    Fast Eddie VIP MEMBER

    Joined:
    Oct 4, 2013
    nuthin’ wrong with a single carb...;)

    D9606839-2821-406B-AAAA-1A450749F7EA.jpeg
     
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  19. montelatici

    montelatici

    Joined:
    Aug 26, 2009
    There you go, since I don't intend to return to racing, much less with a Commando, rubber mounting of the carburetors is not something I would contemplate. Also, the flopping isolastic mounted engine plus adding the flexibly mounted carburetors does not seem like a solution.
     
  20. worntorn

    worntorn

    Joined:
    Dec 22, 2006
    Ive never figured out the desire to run one carb on these two carb bikes.
    Some say it's for tuning ease but there really isn't any tuning to do once it's set. It's easy to set the Amals up if one follows the instructions.
    Once set, you can leave them alone for a long time.
    I've also heard that the single is for improved starting, but how do you improve on one kick or one short push of the button?
    Now I recall that last year when in Mission you mentioned that there wasn't much point in adding the second carb. You figured the Norton already had more pep than your T100 and there couldn't be much there that you were missing.

    Now that it has extra zip with the 2nd carb it must have More than More power vs the poor old T100. So that's quite a bit.

    But then there is a whole world of upgrades for that T100. It's just possible that with enough investment in engine mods it might keep up with the Norton?:)

    Glen
     
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