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Norton 1974 won’t start

Discussion in 'Norton Commando Motorcycles (Classic)' started by phliper, Apr 28, 2018.

  1. phliper


    Aug 19, 2011

    I tried to start my norton after some work on it. Spark plugs are good, carb freshly cleaned up.

    I got spark, but the kickstart kicks back.

    My battery shows 11.9 volts after 2 minutes with the headlight test.

    Should I change my battery?


  2. 84ok


    Aug 10, 2014
    spark plugs are good means?

    ignition sys info? might be a timing issue,

    are u using choke?
  3. phliper


    Aug 19, 2011
    Spark plug =new
    Ignition = Boyer (brand new)
    Yes using choke
  4. phliper


    Aug 19, 2011
    The bike started before the winter.
  5. Triton Thrasher

    Triton Thrasher

    Feb 10, 2009
    What "work" did you do on it?

    Also try starting it while it's connected to a known good battery, such as one in a car.
  6. spelky


    Oct 4, 2009
    As many on here will testify, Boyers normally need a full 12 volts to work ok otherwise they retard the ignition and you get a kick back but you say it's brand new, I seem to think the new ones don't have that problem any more, either way fully charge the battery as a start point. Otherwise it would make sense to just go through what work has been done and eliminate each of those items
    in turn, ie you say the carbs have been cleaned up, what exactly has been done?
  7. piper 600

    piper 600

    Dec 1, 2017
    fuel ???

    any at the plugs ?
  8. Fast Eddie

    Fast Eddie VIP MEMBER

    Oct 4, 2013
    Charge the battery first and foremost.

    Then double check your ignition timing.

    Then try again.

    We all have an unexplainable urge to jump to dramatic hypothesise... but should always double check the basics first.
  9. dave M

    dave M

    Oct 19, 2005
    With a Boyer system the two wires to the trigger plate are not interchangeable, if you fit them the wrong way you will have a fine spark but a lot of retard.
  10. concours

    concours VIP MEMBER

    Dec 29, 2011
    Choke.... Amal? Mik? tickled? a lot? flood then clear it with open throttle if you're unsure, you'll find what it wants along the way....
  11. o0norton0o


    Apr 27, 2015
    since your boyer is "brand new" and your attempt to kick start yields a kick back, that sounds like you are too advanced. Whether that is because you set your ignition up too advanced or your carburation is too lean, finding this out will be part of your discovery process...

    Reread the boyer installation guide for the initial set up. Check that your magnetic rotor hasn't slipped it's position. Verify that the rotor is set at the proper angle (refer to the instructions)

    Pull the plugs and inspect them. Is fuel getting to them? Are they wet? Are they dry??

    Because you are getting a kickback, you know you are getting spark but you don't know that it's timed correctly. Spark timing and mixture are related. Meaning that if you are only a few degrees too advanced AND you are too lean of a fuel mixture, you will get a kickback because that lean mixture burns quicker which amplifies the effect of your timing being advanced... Kickback!

    So, try this to start the bike. Don't use the choke. Bleed the bowls if you have amals. Hold the throttle half open and kick the bike over. It may roar to life and die if you release the throttle. If that's the case, then that may indicate clogged pilot jets on amal carbs if that's the carb you have...

    without knowing what your carbs are, I can only guess.. HTH
  12. ashman


    Jul 11, 2010
    I would start at the battery 11.9 is a flat battery and thats on load when you said it dropped to that when the light was on a fully charged battery is 12.7 round abouts anything lower than 12.5 and its going flat and letting a battery sit for periods of time is not good for them it might charge up but whether it will stay charged is another thing, a load test is the only way to know if your battery is still good after a charge.

  13. phliper


    Aug 19, 2011
    I bought a new one... just in case. The old battery was 5 years old. I won’t take any chance :)
  14. ashman


    Jul 11, 2010
    Thats a good start you got a good run out of that battery.

    phliper likes this.

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