Topic: Ignition problem? Solenoid problem?

[sugarfinger]

Can anyone tell me what would cause the starter to go when I turn the key to on1?

'75 750.  I have a brand new harness from cb750 supply and everything stock except for turn signals and tail light.

Thanks

[Rob69]

Can anyone tell me what would cause the starter to go when I turn the key to on1?

'75 750.  I have a brand new harness from cb750 supply and everything stock except for turn signals and tail light.

Thanks

Sounds like a short circuit. Question: Is the right hand handlebar switch harness routed inside the handlebar? If so, did you remove and install the switch recently, or have the switch apart? To stop it from doing what it's doing, remove the headlight and disconnect the yellow wire with the red tracer until you can track down the problem.

[sugarfinger]

[/quote]Sounds like a short circuit. Question: Is the right hand handlebar switch harness routed inside the handlebar? If so, did you remove and install the switch recently, or have the switch apart? To stop it from doing what it's doing, remove the headlight and disconnect the yellow wire with the red tracer until you can track down the problem.
[/quote]

I forgot to mention I changed the bars.  I had to rewire the right hand controls and the wires no longer run through the bars.

[HondaMan]

Sounds like a short circuit. Question: Is the right hand handlebar switch harness routed inside the handlebar? If so, did you remove and install the switch recently, or have the switch apart? To stop it from doing what it's doing, remove the headlight and disconnect the yellow wire with the red tracer until you can track down the problem.

I forgot to mention I changed the bars.  I had to rewire the right hand controls and the wires no longer run through the bars.

Stock wiring for the right-hand '75 switch: Black is power to the switch, and Black/Red (usually) comes back from the Start button as Headlight power when it is NOT pressed. When you press it, the power comes back on Yel/Red instead, which causes the headlight to go out while START is active.

[Rob69]

Sounds like a short circuit. Question: Is the right hand handlebar switch harness routed inside the handlebar? If so, did you remove and install the switch recently, or have the switch apart? To stop it from doing what it's doing, remove the headlight and disconnect the yellow wire with the red tracer until you can track down the problem.

I forgot to mention I changed the bars.  I had to rewire the right hand controls and the wires no longer run through the bars.

Look for an exposed wire. I had the same problem with my CB350F restoration project. I found the yellow/red wire exposed and grounding out against a metal guide inside the switch at the starter button. It's also possible that the starter button is sticking. If you have an ohm meter and a shop manual, perform the checks outlined in the manual to ensure that the switch is opening and closing properly.

[sugarfinger]

Starter button is functioning properly.  I'll start searching for a short circuit... I can't imagine where though because the harness is new.

The right hand controls have the headlight on/off switch.  The wires are br/wt, bk/wt, bl, bl, y/r, and grn/rd.

[HondaMan]

Starter button is functioning properly.  I'll start searching for a short circuit... I can't imagine where though because the harness is new.

The right hand controls have the headlight on/off switch.  The wires are br/wt, bk/wt, bl, bl, y/r, and grn/rd.

Did you buy an EGO harness (PartsNmore, et al?). The Yel/Red and Grn/Red wires that run the Starter solenoid might be screwy. I just had to rewire one of those today: made a male-male Yel/Red to connect to the solenoid from the harness, and tied the solenoid's Grn/Red to the spare Grn under the seat with a male spade on one end, female bullet on the other, 1" long jumper(s). This EMGO PartsNmore harness presumes a grounding START button at the handlebars, has a female Blk at the starter solenoid (as in K0-K2 bikes), yet it is listed as a K3-K6 harness. Seems to be a kitbash of 2/3 of both harness types?

[sugarfinger]

Did you buy an EGO harness (PartsNmore, et al?). The Yel/Red and Grn/Red wires that run the Starter solenoid might be screwy. I just had to rewire one of those today: made a male-male Yel/Red to connect to the solenoid from the harness, and tied the solenoid's Grn/Red to the spare Grn under the seat with a male spade on one end, female bullet on the other, 1" long jumper(s). This EMGO PartsNmore harness presumes a grounding START button at the handlebars, has a female Blk at the starter solenoid (as in K0-K2 bikes), yet it is listed as a K3-K6 harness. Seems to be a kitbash of 2/3 of both harness types?

Harness is aftermarket so probably.  I got the starter switch working by attaching the yel/red on my switch to the yel/red on the harness and attaching the grn/red from the switch to the lt grn/red on the new harness.

I have a few more gremlins to figure out now but I'm close.  I'm gonna do more searches here before I ask a dumb question.  Thanks to all for the help thus far... I would be lost without this forum!

[Bristledisk]

Thanks to this 10 year old post, my problem with my 350F whereby the starter motor kicked in as soon as the key ignition was turned on, but before the starter button was pressed, is solved. The yellow/red wire was grounding in the Right Hand switch. I repaired the frayed wire, and the starter motor now comes on only after started button is pressed.

[HondaMan]

Thanks to this 10 year old post, my problem with my 350F whereby the starter motor kicked in as soon as the key ignition was turned on, but before the starter button was pressed, is solved. The yellow/red wire was grounding in the Right Hand switch. I repaired the frayed wire, and the starter motor now comes on only after started button is pressed.

Good sleuthing!