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

what is involved adding a tach drive to a '61 ES2 500 single?

Discussion in 'Other Norton Motorcycles' started by JamesWeyand, Aug 14, 2019 at 4:41 PM.

  1. JamesWeyand

    JamesWeyand

    Joined:
    Aug 10, 2019
    What is the process for adding a tachometer drive to a 1961 Norton ES2 500 single? I'm thoroughly confused with all the different drive ratio information out there and need help from the experts on what's right for my engine.

    I just posted a wanted ad for a timing cover with tach drive already installed but if I can't find one for sale, does anyone know a member or good machine shop that can perform this modification on an ES2 and install a functional tach drive?

    Jim in Seattle
     
  2. Bernhard

    Bernhard

    Joined:
    Apr 20, 2011
  3. L.A.B.

    L.A.B. Moderator VIP MEMBER

    Joined:
    Nov 20, 2004
    Camshaft driven tach drive gearboxes are generally 1:1 ratio (either reversing or non-reversing) to suit 2:1 rev counters (Atlas, SS) or 2:1 (rev./non-rev.) to suit 4:1 revcounters (20M3 Commando).
     
  4. Bernhard

    Bernhard

    Joined:
    Apr 20, 2011
  5. Fast Eddie

    Fast Eddie VIP MEMBER

    Joined:
    Oct 4, 2013
    Might it be easier to consider and electronic tacho?

    If it’s coil ign you could used an original looking smiths job.

    If it’s magneto that won’t be possible but you could use something like a Scitsu.
     
    jan nelder and johnm like this.
  6. ntst8

    ntst8 VIP MEMBER

    Joined:
    Feb 14, 2004
    My thoughts too. Featherbed singles were coil ignition from new so should be simple, and the smiths chrono replicas have the step function on the needle movement so look original.
     
    jan nelder likes this.
  7. Bernhard

    Bernhard

    Joined:
    Apr 20, 2011
    Re; “If it’s magneto that won’t be possible but you could use something like a Scitsu.”

    Tut..Tut – it’s not a timing cover you need, as the mag is already reduced to 4:1-what u need is a 1:1 rev counter drive, like on the BSA in pictures, fit a big nut with suitable slot on end of magneto, fit clay/plasticine into top of timing cover push on and then drill in the centre a pilot hole followed by a bigger hole and drill the two holes for the bolts, welding two nuts on the inside.

    The 500 Gold Star shows how its done;


    http://onlymotorbikes.com/public/16/bsa-500-ss-gold-star-1972-moto.jpeg

    https://www.bing.com/images/search?...ar&selectedindex=16&ajaxhist=0&vt=0&eim=1,2,6
     
  8. marinatlas

    marinatlas

    Joined:
    Nov 4, 2007
  9. Bernhard

    Bernhard

    Joined:
    Apr 20, 2011

Share This Page