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Any ignition experts out there? Honda S65.

  • 15 Jun 2021 11:13 AM
    Message # 10642495

    Slowly losing my mind over an ignition problem with my S65 and I'm hoping someone here can help. 

    1965 Honda S65. The bike is stripped down to the barest essentials wiring wise. There’s a primary coil, condenser, main ignition coil, points, and a plug. There is no battery or lighting circuitry installed.

    All ignition components are new - primary coil (NOS), condenser, points, and main ignition coil.

    With the ignition coil disconnected, when I spin the engine I get a nice, blue spark when I touch the lead from the capacitor to ground. From that I assume the primary coil and capacitor are working and generating current. 

    However, when I wire in the ignition coil, if I strip the plug cap off I do get a very weak spark from the high tension lead to ground, but it's not enough to jump any gap.

    At this point I should say that I have 3 separate coils, all of which exhibit the same behaviour. All 3 coils bench test as okay with a resistance between the high tension lead (plug wire) and ground of about 9-10 k-ohms.

    The engine is well grounded to the frame.

    Clearly I'm missing something, but staring at the bike for hours doesn't seem to be bringing it to front of mind.

    Any ideas? Suggestions? 

  • 16 Jun 2021 10:18 AM
    Reply # 10648693 on 10642495

    I dont know  how u got a nice blue spark from the primary coil ,[ at capacitor ] it only puts out about 30V .... U should see that at ignition coil which puts out about 20KV ...

    Assuming all is correctly installed ... That means even ignition coil bolted down for good ground > U should get a great spark ... BUT if you accidently connected primary coil to lighting coil > U  get nothing ... ALSO if your " KILL " wire is connected > DISDCONNECT  IT  !!!

  • 17 Jun 2021 10:21 AM
    Reply # 10655184 on 10648693

    Thanks for the comments George.

    It won't jump much of a gap, but I am getting a nice spark out of the primary.

    I think everything is installed properly. From the primary coil, one lead goes to ground, the other to the capacitor. From the points, one side grounded (through the mount), with a lead to the capacitor. And a lead from the capacitor to the ignition coil, which is grounded through the mount to the frame. 

    There is no lighting coil installed, so that's not the issue. And there's no kill wire connected to the ignition coil.

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