Intermittent no spark condition

Discussion in 'Electrical' started by Bubbaglide, Oct 16, 2008.

  1. Bubbaglide

    Bubbaglide Member

    Ok here are the basics....95 Ultra classic, carbureted with SE aircleaner, V&H true duals and SE slip ons. The problem:

    I rode to wwork one day shut the bike off and it would not fire up. Got it home and checked everything I could. Nothing. Next day it fires right up. Made a short run and cut it off. Fired it back up and rode 50 feet and it shuts off. Sit a minute and it fires back up.

    I changed the coil with a new one and the ignition module with one known to be good. No problem, cranks and runs perfectly. No problem for 3 weeks. Now this morning I fire it up to come to work and 4 miles down the road, it just quits, I keep the clutch out and can smell gas, then all of a sudden the bike backfires and runs like a top.

    Since it's carbed I have no trouble codes to refer to. What should I look at or check ? I hate to get stuck somewhere.


  2. glider

    glider Veteran Member

    Did you notice of the lights went out when it died?

    Could be the main breaker.
  3. hntwrobin

    hntwrobin Active Member

    How's the battery?
  4. glider

    glider Veteran Member

    How's the connections on the battery?
  5. TQuentin1

    TQuentin1 Well-Known Member Staff Member Moderator



    After you have checked out the battery terminals (actually remove, clean both sides and then remount), and the circuit breaker (probably should just go with a new one - check if you are supposed to replace with the 50 amp), look at the info below.

    Had similar problems on my '91 Dyna. Turned out to be the bar switch was all corroded up. Dissassembled, cleaned everything up, used some very fine emory on the contacts, sprayed clean very thoroughly with contact cleaner, lubed with silicone based spray, reassembled and mounted back on the bar. No problems since. Was a chore to figure this out. I went through all the hard stuff first!! Check it out.

  6. Bubbaglide

    Bubbaglide Member

    Thanks to all who replied. To answer questions, battery is ok, charging system is ok, brand new battery cables (within the last two weeks.) Tightened them the day before the no spark condition. and the lights remained on during the event.

    TQ by the bar switch, I'll assume you meant the kill switch. I'm going to check the switchs and buttons on the handlebars to see if something is grounding there.

    Thanks again

  7. SledDog

    SledDog Senior Member Staff Member Moderator

    Maybe it's an intermittent cam position sensor. I had same type of problem with my 96 Dyna. It would run great, shut off, and would not restart. Wait a few minutes, it would either back fire thru the carb or it would fire right up. If it back fired, I would wait another 15 minutes or so and it would fire right up.

    It was under warranty, so I took it to the dealer.. Their answer "no problem found". The next time it happened, I ran the trouibleshooting for the ignition system and found the cam position sensor was intermittent. Got that changed and it solved the problem.