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  1. #1
    CB750 New Member Brian Keller's Avatar
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    1976 CB750A Changing relay wire help

    I just started restoring this Ď76 CB750A and Iím curious about a wire that goes from the solenoid to the changing relay. Itís yellow with a red stripe. It appears that somebody cut the wire at the starter solenoid and spliced a ring terminal to it and grounded it to the frame. They did an excellent job, and Iím wondering if this was a dealer recall repair. Can someone please pop the left side cover and see if itís the same? Thanks!

  2. #2
    CB750 Addict Medyo Bastos's Avatar
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    One side should go to ground in order to complete the circuit.


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  3. #3
    CB750 New Member Brian Keller's Avatar
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    Hi. Thanks for responding. It just doesn’t look factory. The wire (Yellow with red stripe) from the changing relay is not plugged in at the solenoid and there is no place for it. There is a yellow wire with a red stripe from the solenoid that has been spliced (with shrink tubing) To a black wire with a ring terminal and grounded by the fuse block. It appears that the yellow / red wire from the solenoid had the connector cut off and the black wire with the ring terminal added. So should the wire from the changing relay not be plugged in? Thanks.

  4. #4
    CB750 Guru amc49's Avatar
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    All that matters to you is does the starter work when the button is pushed. If so then leave it exactly the way it is.

    The starter solenoid circuit can be double ended in the way it gets wired. Some have power going in the yellow/red and others have that wire as the ground. It can work either way as long as the other wire needed goes where it needs to as well.

    Whether something looks OEM is meaningless if you understand how the circuit works, I have reversed the wires more than once to save $$$$ to use a $20 solenoid that works fine instead of an overpriced one at like $80. Just to look 'OEM'. There are internal grounded solenoids as well as external, either will work as long as wired correctly. I've been using a $20 riding lawn mower solenoid on mine for many years. Works perfectly.

    Honda changes that circuit up too, the SOHC is backwards from the DOHC in that exact yellow/red wire useage. The SOHC uses it as the ground for solenoid, the DOHC uses it as power to the solenoid. It gets flipped on the later models to make the grounds partly green (green/red), it lends to recognizing green as a Honda ground color and the extra starter interface switches complicate the ground wire more anyway. Using yellow/red there would confuse things more.

    I would suspect the handlebar starter button to be wired slightly different based on that solenoid mod.
    Last edited by amc49; 07-08-2020 at 07:25 PM.

  5. #5
    CB750 New Member Brian Keller's Avatar
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    Thanks for the info. I was told that this bike was parked 20 years ago because it would not start. The owner thought it was a wiring problem, and since I’m an electrician, I figured it wouldn’t be too hard to get it running. Sure enough, I found wires that were plugged into the wrong place. The engine now turns over and I’m getting spark on all four plugs. Rebuilt the carburetor’s and install those today. Should be able to attempt to fired Up this weekend. Thanks again

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