1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

Single to Dual Amal Setup

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

  1. HRD


    Mar 21, 2011
    Is the two into one throttle cable junction box the original or a replacement type,there are different inner cable measurements for different junction box types.
  2. ashman


    Jul 11, 2010
    You need a shorten allen key, the orginal tool kit that came with my new Norton had the shorten allen key in the kit for the manifolds, its the only tool I have left from my orginal tool kit.

    Tornado likes this.
  3. Tornado

    Tornado VIP MEMBER

    Dec 5, 2017
    It is a new splitter, black plastic. Unsure if Amal or some other make, baggy didn't have labels.
  4. Tornado

    Tornado VIP MEMBER

    Dec 5, 2017
    Seems to be case but I. Will contact supplier to see if there was a mistake before cutting anything.
    Curious, is there a way to add some sleeve length by splicing in a short bit of extra sleeve? Seems that would achieve desired free length without needing to learn how to fit a nipple.
  5. MexicoMike


    Jan 31, 2010
    FWIW, I'd say that it's not really "fair" to go from a good-running single Mikuni to original 932's with new slides and get the improvement you may be hoping for. It is entirely possible that the original Amal bodies are warped and the new slides won't mate as well as they should. I'd suggest a new set of Premiers for this "re-conversion." That being said, I realize that if you are just doing it to try out, it's a lot cheaper to NOT buy a pair of new carbs. ;)
    Nater_Potater and concours like this.
  6. Fullauto

    Fullauto VIP MEMBER

    Apr 13, 2009
    First prize was one Anal, Second prize was two Anals.
    Atlas Commando and Fast Eddie like this.
  7. Tornado

    Tornado VIP MEMBER

    Dec 5, 2017
    Bike came with two amals but with only the single setup installed, from DPO.
  8. baz

    baz VIP MEMBER

    May 26, 2010
    There speaks the voice of experience!!! Ha ha
    Whilst my head agrees with you my heart tells me two amals and use the bike for what it's designed for
  9. gortnipper

    gortnipper VIP MEMBER

    Nov 11, 2013

    *sans O
  10. MexicoMike


    Jan 31, 2010
    AND... the twin Amal bike - ASSUMING the carbs are in like-new condition and properly jetted - will walk away from the single Mik bike at WOT as the RPM passes 4k. Also, don't expect a stock 850 with the single Mik to do the ton...at least in any reasonable distance; the twin Amals will have no trouble.

    Whether you care about doing the ton is a different issue! ;)

    Of course, the single mik with a real choke is a lot less messy for starting than dual ticklers!
  11. baz

    baz VIP MEMBER

    May 26, 2010
    We must be careful here as it could degenerate into a single verses twin amal debate (again)
    The bloke wants to try twin amals on his Norton
    Everyone has an opinion
    I'd say go for it,sure if the carbs are worn it'll play up low down but the top end will still be there
    On my own commando I have gone back to twin amals and the bikes carburetion is spot on, although I will at some stage re fit the 40mm pumper when my carbs wear out
  12. L.A.B.

    L.A.B. Moderator VIP MEMBER

    Nov 20, 2004
    The upper cable is possibly wrong as there are two different inner cable lengths (regardless of overall length).

    = 3.06" standard, and 2.44" for the later 'Quick action' twist grip.


    Edit: 'Throttle' and 'choke' lower (carb end) cables have different length inners.
    Last edited: May 23, 2019
    nortriubuell likes this.
  13. Tornado

    Tornado VIP MEMBER

    Dec 5, 2017
    Thx LAB for those measures. I will check what I have.
    Do I take the nipple lengths into account for the free length dimension or just the cable section between nipple and sleeve?
    Watched a few viddys on making up cables. Seems nipple can come off with heat and knocking with a pair of pliers. Refitting by flaring out strands to hold nipple then soldering to make fast. Can give it a try with older cables. Got a couple HiRider length off bike someplace.
  14. Deets55

    Deets55 VIP MEMBER

    Oct 3, 2013
    After making a couple of throttle cables some of the things I learned were,
    1) Use a heat sink on the running cable side of the nipple. If the cable gets hot solder can flow into that area and cause a stress point.
    2) Keep the factory nipple on the carb end. If the DYI connection breaks the nipple won’t drop into the carb
    3) Use a dab of flux on the cable before you solder
    4) If the cable is stainless you will need special flux and solder.
    5) Clean and degrease the area well
    I’m sure there are other things to worry about, but that’s all I recall

    This might be helpful

    Tornado likes this.
  15. Tornado

    Tornado VIP MEMBER

    Dec 5, 2017
    So the upper cable has the wrong grip nipple...it is a thinner disk than my older single carb length cables, basically the same as what the choke control uses. And the bag it came in indicates it's for a Triumph. Free end length comes out as here (lower cable is dual type with adjuster, upper is single carb cable) with adjuster at max unwound:


    Or with adjuster full wound in:

    Note nipple ends compared to single carb cable above it.
  16. Craig

    Craig VIP MEMBER

    Dec 20, 2005
    Yep , have dealt with all those issues in the past , I now have a collection of cable ends in a baggie ... the instructions above are excellent , you should use them as reference .... you getting very close to having a dual carb setup .... good luck !
  17. Tornado

    Tornado VIP MEMBER

    Dec 5, 2017
    OK talked to supplier and we discussed how to make a more informative measure of the excess. With the cables all connected up to carbs, pull the sleeve away from grip until free movement gone, before throttle spring tension occurs. Measure how much excess inner cable emerges from grip mount. Here's what. I got at both extremes of upper cable adjuster settings:


    So around 3/4" to 1-1/8" taking the second band on the sleeve endcap as the datuum point (it sits just outside the grip mount recess when sleeve is fully inserted).

    Supplier says he can make up a new cable and send it out today.
  18. acotrel


    Jun 30, 2012
    If I was doing that, I would not use a junction box. Thomaselli sell twin cable quick action twist grips and most sellers of Japanese bikes have suitable separate nylon-lined cables for sale. I have fitted twin carbs in place of a single carb on Triumphs and not noticed any difference. It is easier to tune a single carb and a well tuned single carb is probably better than sloppy twin carbs.
  19. worntorn


    Dec 22, 2006
    My Rapide had nylon lined cables. They are good until used in an all day rain.
    When in that situation the hygroscopic nature of nylon caused swelling which in turn caused the throttle to stick open.
    I had this problem on a couple of trips then switched all of the cables over to Venhills Featherlight Teflon lined. Teflon is even more slippery than nylon plus it isn't hygroscopic.

    Problem solved.

    Last edited: May 24, 2019
    Nater_Potater likes this.
  20. Fast Eddie

    Fast Eddie VIP MEMBER

    Oct 4, 2013
    I will only use Venhill Featherlight, unless there’s no other choice. The difference in feel and lightness is noticeable.

Share This Page