No Spark on airhead, something stupid no doubt

Discussion in 'Old's Cool' started by jtwind, Mar 28, 2007.

  1. jtwind

    jtwind Wisconsin Airhead

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    I got my 86 g/s out of storage yesterday. Put the battery in along with a IMO, a tourtech speedo/tach that was out to have a new screen put in.
    Won't start, gas but no spark. Lights, starter etc. all working. So I tried new plugs, no go, different wires the same, I tried a known working coil, nothing doing. I tried a spare ignition module, again no joy. Last thing is the hall canister, so I tried the center plug test, no spark. Which should tell me the module is bad but I'd already tried a new one. So, I think I'm overlooking something really dumb. But what? Any ideas out there? Don't spare me the obvious, it's probably the problem. Must be getting old. Thanks, JT
    #1
  2. Stagehand

    Stagehand Imperfectionist

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    high impedance air gap somewhere?


    usually my problem. devices are often fine.. its almost always me.

    where the last place you have good 12v?
    #2
  3. Wirespokes

    Wirespokes Beemerholics Anonymous

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    Good one JT. My first thought was the Hall unit - my G/S wouldn't start when I went to buy it, even though it ran fine six months before when it was parked. You can check the coil, wires, and plugs this way: Remove the ground side connection to the coil. Apply +12V to the coil positive terminal. With a jumper, ground the negative (ground) coil connection. You should get a spark every time you short it to ground.
    #3
  4. jtwind

    jtwind Wisconsin Airhead

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    TVRLA, Thanks, I do get a spark with that test. I guess that does leave me the ignition module or the hall canister. I have a suspicion though that I'm overlooking something. JT
    #4
  5. datchew

    datchew Don't buy from Brad

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    Remember the Alamo!
    You said you're getting gas... I assume you looked inside the plug holes and saw it right?

    Valves are tuned and all that? How bout timing? God forbid you have a timing chain problem, but hook up that timing light and crank it over a few times just to be sure.

    This may sound dumb, but all those parts you swapped out... did you put the old ones back each time? reason I ask is it may be a combination of bad parts. Put all the for-sure working ones in and don't go back during the swap and test process.

    maybe squirt some starting fluid in the plug holes. Man... i'm stumped. Good luck. Keep us posted.
    #5
  6. datchew

    datchew Don't buy from Brad

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    oh, one more thing... when you tested the plug wires, you probly used a multimeter and pulled them off the bike to do it.

    I had trouble once where it was a sporadic break in the line. had to be twisted just the right way and it would fail the test. Might try bending/wiggling the plug wires
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  7. Foot dragger

    Foot dragger singletracker

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    We had to change out the plug wires in whitehorse on a 93 GS, They had turned green up inside the coil and much scraping and cleaning later,and a trip to the whitehorse honda shop for new wires and we were on our way. Youre sure theres no corrosion anywhere?
    #7
  8. jtwind

    jtwind Wisconsin Airhead

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    Well after replacing every part in the ignition system and getting nowhere, I was more convinced than ever it was something stupid. It is, but not by me. As I mentioned I put the IMO back on that I had to send back to Tourtech for a screen replacement. The IMO if you don't know is a LCD speedo, tach, odometer etc. Anyway, on a hunch I disconnected the tach lead from where it is supposed to be on the unit and voila! it starts. The goofy idiots at Tourtech always so smug that nothing is ever their or their equipments fault, somehow fixed the unit so it shorts the coil lead. Or something. I have a phone call into them at present. To say I'm a bit perturbed is an understatement.

    Did I mention I've been doing all this out in the rain? One of those days. Thanks for the ideas guys. JT
    #8
  9. datchew

    datchew Don't buy from Brad

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    At least it's fixed. Glad it wasn't something more vital like a bad valve or something.
    #9