Pop pop Ds engine cuts out?

Discussion in 'Norton Commando Classic Motorcycles' started by auldblue, Feb 13, 2018.

  1. auldblue

    auldblue VIP MEMBER

    Joined:
    Nov 20, 2012
    750, Boyer Mark 1V, podtronics reg/ rec ,+ earth, 6v coils. Thought I'd checked everything HT leads ,pick up , battery good , coil resistance, primary and secondary. Rided in rain never a problem but it's started cutting out in the dry and in the wet . Pop pop D/S and stops ,no missing , the only thing is the spark seems week tried new coil but didn't replace and Boyer pick up still the same. Has anyone (les) got any form of explanation ? Dead short , bad connection?

    Cheers
     
    Tags:
  2. NortonMKIIA850

    NortonMKIIA850

    Joined:
    Jul 20, 2017
    My first thought would be, are the Boyer wires fractured under the points cover? If so, there are fixes ... Good luck.
     
  3. worntorn

    worntorn

    Joined:
    Dec 22, 2006
    Rule out a faulty /corroded ignition switch by fitting a jumper or bypass wire.

    Glen
     
  4. Esmerela

    Esmerela VIP MEMBER

    Joined:
    Jan 9, 2017
    Maybe try bypassing the ignition switch and the kill switch. Run a live direct from the battery to the Boyer and make sure the earth /ground connection is good, reduce the possibles problems to the minimum.
     
  5. auldblue

    auldblue VIP MEMBER

    Joined:
    Nov 20, 2012
    Cheers for the replies . I have been through these faults to the best of my abilities and having had kill switch and ignition switch failures in the past theses do not appear to be causing the pop pop on power loss . Have also had a good go at the Boyer wires as it is a common fault these also seem in good order.

    My next step is to heat the coils and test but the problem occurred after start up on riding a half mile on two occasions so I had discounted heat but will test anyway. I was hoping for some inspiration to save the old perspiration before fitting a new Boyer ,coils and wiring!

    Cheers
     
  6. Craig

    Craig

    Joined:
    Dec 20, 2005
    Your coils are pristine condition , never over tightened.... just a thought
    Craig
     
  7. auldblue

    auldblue VIP MEMBER

    Joined:
    Nov 20, 2012
    The coils look undamaged and test ok, but they were not the most expensive NOC spares I think from memory. I can rob new coils from another bike or probably best order a new set grease them up and see what occurs. Thanks Craig

    Cheers JG
     
  8. Craig

    Craig

    Joined:
    Dec 20, 2005
    Hope that cures your ills ... let us know how you make out , thanks
    Craig
     
  9. concours

    concours VIP MEMBER

    Joined:
    Dec 29, 2011
    My broken wires on the Boyer pick up plate displayed that exact set of symptoms
     
  10. acotrel

    acotrel

    Joined:
    Jun 30, 2012
    Petrol tank breather not blocked ?
     
  11. auldblue

    auldblue VIP MEMBER

    Joined:
    Nov 20, 2012
    Cheers Allan, petrol flow fine ,no air lock . Again seen it before and it's good.
    Cheers
    Tested and seemed ok but by the sounds of it that could indeed be the problem. I'll have it off and send it back to Boyer for testing, I'm going to replace the d/s coil also and see if there is a fatter spark.

    Cheers Jg
     
  12. baz

    baz VIP MEMBER

    Joined:
    May 26, 2010
    I had a problem recently where the left coil had gone bad but was still sparking but the right coil which was good was not sparking at all because of the link wire from the left coil not powering it up,this caused the same symptoms you describe, cheers
     
  13. cliffa

    cliffa

    Joined:
    May 26, 2013
    JG, if you still have the short tails on the stator plate, and there is a cable tie directly one the wires with no piece of rubber between them, it’s highly likely that wires have broken inside the insulator. See my thread called “ Almost Stranded” for more details. I happily convert yours if you want to send it to me. PM me if you are interested.

    Cheers,

    cliffa
     
  14. kommando

    kommando

    Joined:
    May 7, 2005
    If it starts to go pop pop on one side before finally dying then check the engine earth, if its dropped to a few strands then it can only support one coil firing at a time.
     
  15. concours

    concours VIP MEMBER

    Joined:
    Dec 29, 2011
    Wiggle the wires between frame & timing chest while it's idling.
     
  16. concours

    concours VIP MEMBER

    Joined:
    Dec 29, 2011
    That's where mine had failed too. Pulling on the wires outside was enough to show it, as mentioned above. Quick/easy test. You MAY get a false negative, but not a false positive.
     
  17. JimC

    JimC

    Joined:
    Oct 12, 2007
    Quite a contrast to the thread a few days ago where the Boyer ignition was being touted for its reliability. My experience with the Boyer has been a broken wire on the pickup plate, causing a misfire on one cylinder until revs exceeded ~2,000 rpm. Harmonics? Wringing those wires out by moving them about while monitoring continuity will uncover the culprit.

    Boyer didn't get a bad rap. Any manufacturer of any motorized vehicle or machinery electrical equipment should know better than to solder wires unless those wires are potted. Tightly tying soldered wires to a board won't cut it when used in a vibrating environment. And I don't give a damn about testimonies to the contrary.
     
    Last edited: Feb 14, 2018 at 6:06 AM
  18. oldmikew

    oldmikew

    Joined:
    Jul 25, 2015
    The original Boyer pick up had a screw terminal block - it was fairly good . With the mk4 plate it is possible to have a broken wire within the insulation the ends of which might make erratic electrical contact but come apart at certain engine revs causing a very difficult to trace misfire
     
  19. auldblue

    auldblue VIP MEMBER

    Joined:
    Nov 20, 2012
    Seem to have found a culprit d/s coil has a crack. I am a bit knackered so have called it a night will try Boyer wires tomorrow. The rest of the wires ,earths etc seem ok but will give them a good rattle and see how she runs. Thanks for the help will post the outcome of repairs.

    The Dragon rally was not the best place to have issues though. Cheers Jg
    image.jpeg image.jpeg image.jpeg
     
  20. PJFlynn

    PJFlynn

    Joined:
    Apr 26, 2017
    Riding and camping in the snow doesn't look like a whole lot of fun.
     

Share This Page

Loading...