74 z50 no spark and no idea why.

Discussion in 'Pit Bikes & Mini's' started by andthereyouare, Mar 28, 2006.



  1. andthereyouare

    andthereyouare Rookie DRN Member

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    Hey all, I'm new here.

    I read some threads on my topic and have tried numerous ideas... Here's my problem I received a Honda 1974 z50. There is no rust at all on it. It sounds like it has good compression, but I have "No Spark". I'm not sure when it actually ran last. So I replaced every piece of electric portion on the bike, except the tail light.
    All brand new:
    1) Ignition Coil
    2) The entire Stator ((capacitor, points and coils) Gapped the points to the manual settings)
    3) Complete wire harness
    4) Kill Switch
    5) Dimmer Switch
    6) Spark Plug (Gapped it according to Manual)
    7) Headlight

    I'm not sure what the spec is for the electrical current through each item but I am getting voltage. I put the spark plug on the block and crank it with no spark to be seen.

    Oh and I'm not a motorcycle mechanic, so I'm learning. I'm thinking this is the same scenario as you would have on a push lawn mower with a pull start, right?

    Any ideas would be awesome!

    Thanks,
    Jim


  2. 83MX80

    83MX80 Rookie DRN Member

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    hmm thats weird that you've replaced pretty much the whole electrical system and still having troubles with it. is it shorting out somewhere? i'd peel off all the plastics and inspect all the wires to see if they are bare/uncovered and put a test light on it. thats really all i can think of. sorry.
  3. TimberPig

    TimberPig Rookie DRN Member

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    Start at the source and work out. If you've got spark being generated at the stator, and it is making its way to the coil, then check the coil. You said you had a manual, so look in there for the test specs. If it checks out, then check the plug wire and cap. If thats good, try the plug in another engine, or another known good plug in yours. Also try to check the spark in dim light, as it makes it easier to see. Also disconnect the kill switch to isolate the possibility of that killing your spark. The only part you haven't replaced thus far is the flywheel, which if the magnets in it are weak, can kill the spark. Check the other stuff first though, as flywheels rarely go bad. I suspect you've simply got a bad connection somewhere.
  4. andthereyouare

    andthereyouare Rookie DRN Member

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    I'm in the process of rechecking with the meter. Yea, I read that it's rare that flywheel magnets go bad. Knowing my luck so far it's totally possible. Thanks and I'll post anything I find out with this wave of tests.



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