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  1. #1
    CB750 Member baldjeff's Avatar
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    Starter Solenoid Help

    Hi all, I'm rewiring my '81 CB750C. I just got to the starter solenoid, which I assume is the original, OEM unit. I see the 4 male connectors go to the reg/rec, starter switch, ignition switch, and clutch diode but I'm unable to find out which one is which. Is there a way to test them? Does anyone know what they are off the top of their head? If I'm not running the clutch diode can I just leave that one alone? Thanks!

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  2. #2
    CB750 Guru amc49's Avatar
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    Neutral circuit (clutch diode) is green/red.
    Power to ignition switch red.
    Charging output from regulator to battery is red/white.
    starter circuit is red/yellow.

    You have to positively change something up, you can't just drop the diode-gone the neutral switch won't work. The leads tied together with no diode will cause starter circuit issues.

  3. #3
    CB750 Member baldjeff's Avatar
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    Quote Originally Posted by amc49 View Post
    Neutral circuit (clutch diode) is green/red.
    Power to ignition switch red.
    Charging output from regulator to battery is red/white.
    starter circuit is red/yellow.

    You have to positively change something up, you can't just drop the diode-gone the neutral switch won't work. The leads tied together with no diode will cause starter circuit issues.
    Thanks AMC. I should've been more specific with my question. I don't have access to the original harness so I can't tell which wire connected to which connector. Do you know which is the upper left, upper right, bottom left, and bottom right connectors?

    Would the circuit issues result because of this particular starter solenoid? What would be a potential solution if I didn't want to run the clutch diode? If I bought a new solenoid would it eliminate the issue?

  4. #4
    CB750 Guru amc49's Avatar
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    The clutch diode prevents conflict between the neutral light and the clutch handle starter safety switch. Not being there power can go backwards from neutral into the clutch switch in a direct short. Battery runs down if not a fire outright.

    You need skills to do that workaround as well as to easily find the location of your solenoid wires but not having them (your questions show it) means a 500 page book needed by you. Your not having a OEM harness is going to cripple you there if you cannot freely wire alone with no copy to follow, there are necessary crossovers and interfaces built into the harness that you will not be aware of at all.

    Last paragraph questions answered.......

    1 No.
    2 Answered above.
    3 No.

  5. #5
    CB750 Member CR9000's Avatar
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