Topic: Starter Switch Wiring Help!

[HairyPotter]

I need wiring help, please.
I have a 1976 CB750K but I'm not sure if the switches/wiring I have are from that model, so I'll describe what I've got and hope you can make sense of it.

I bought the bike with the starter button broken. The PO had another after market generic starter button mounted to the frame just under the helmet lock. When I got the bike I took the original switch apart and found that the button itself had deteriorated. I've replaced that, and now I want to hook the original starter switch back up.

Two wires come off of the starter switch- G/R and Y/R. Down at the starter, the solenoid has two posts, one going to the starter, and one going to the positive of the battery. There are also two wires coming off of it, a G/R and Y/R.

PO had the Y/R hooked up to one lead of the after market starter. He had the G/R going right to the ground terminal of the battery. He also had the second wire coming off of the aftermarket starter going to the solenoid post that is connected to the positive post of the battery.

Down by the fuse box, I found two empty pigtails Y/R and Black. I'm thinking the Y/R went to the starter solenoid some how. I have continuity from it to the starter button. Also, get continuity between the G/R at the starter button and the Y/R pigtail when I press the starter button.

I feel like I'm close, but can't seem to get the original starter button to engage the starter motor.

I've looked at the wiring diagrams from the different models can't find any that exactly fit what I've got.

Can anyone help me at this point? It's a magnificent day and I'd like to get a ride in with then new starter button intact.

Thanks in advance. You guys have been a great help in the past.

B

[Triffecpa]

The early Honda starter solenoids (before they started tacking fuses onto them) were quite simple.  The large cables go from the battery to the solenoid and then from the other solenoid post to the starter.  The Y/R and G/R wires are there to generate magnetic push on the brass plate that pops up to temporarily connect the two posts so that the positive charge will go directly to the starter.  What you want is a hot lead to the Y/R wire and then the G/R wire is a ground wire that goes thru the starter switch.  All the switch does is complete the ground circuit.  So if the G/R wire runs to the switch, the second wire on the switch either runs directly to the frame or to the negative side of the battery.

TR

[HairyPotter]

I'm confused. At the switch I have a Y/R wire that goes all the way down to the starter. There is also a G/R but I don't know where it goes to. When I hook my multi-meter with one end on the Y/R wire down at the starter and one end on the G/R, I only get continuity when I push the starter button.
Otherwise there is nothing.

The PO had the two wire after market switch hooked up with one wire going to  Y/R wire coming off of the solenoid, and one wire going to the solenoid lead connected to the positive battery.

Like I said, I don't know where the G/W coming off of the original starter switch is going or how to get it to connect to the starter. Shouldn't I just be using the Y/R wire that runs from the switch down to the starter area? I have continuity. Am I missing something? I know this is simple... I'm just not getting it.

Thanks

[HairyPotter]

Okay... when I hook the hot lead from the stater solenoid to the Y/R pigtail I have down at the starter area, my lights and oil light come on, even with the key off. Do I have a short somewhere?

[HairyPotter]

I've now determined that trying to track down an electrical short on a 32 year old motorcycle is like chasing Pi...

[WFO]

http://www.google.com/imgres?imgurl=http://www.rnrfabrication.com/Wiring%2520Diagrams/yamaha1974tx650a-wiring.jpg&imgrefurl=http://www.rnrfabrication.com/wiring.htm&h=1049&w=1503&sz=215&tbnid=AX545GLfTQMJ:&tbnh=105&tbnw=150&prev=/images%3Fq%3D1976%2BCB750K%2BWIRING%2BDIAGRAM&sa=X&oi=image_result&resnum=1&ct=image&cd=3

[TwoTired]

You need a wire diagram for a 76 750K. (pg 252 of the Honda Shop Manual.)

Your starter button must have three terminals for this model.  It switches power to either the headlight fuse (at rest) or to the starter solenoid (when pushed), on the Y/R wire.
The Y/R wire goes direct to the starter solenoid, and is supplied power via the starter switch from a Black wire source.

The G/R connection to the solenoid supplies Battery NEG connection (usually a Green connection), via either the Clutch switch or the Neutral switch.  the neutral LG/R wire is connected with a Diode to the G/R cuircuit, so the neutral light doesn't com on when the clutch is pulled in.

If your control only has a two terminal starter switch then you will have to create a hybrid electrical system to adapt parts from different models.  Earlier models had a Starter Safety Unit to provide power to the solenoid, instead of direct from the starter switch.

A review of your goals or a statement of how you want it to work and what parts you have available is necessary to provide any further help.

The Link provided by WFO does not seem to include a diagram for a K6.  But, likely your starting circuit is more like the K8 than earlier models.

Cheers,

[HairyPotter]

Okay,
On my right hand switch assembly, I have a starter button, a three position engine kill switch and headlight on/off switch. The after market switch I've been using has only two wires. I would like to use what appears to be the original two wire starter button to start the bike. I would like somehow to use the wires already present in the wiring harness rather than run a separate wire from the button to the starter.

Prior to this, the bike would try and start when it was in gear, so I'm thinking that if it has a clutch switch, that's been disconnected somewhere.

Is that enough information?
Thanks.

[HairyPotter]

Okay... I figured it out. Bike starts using the original starter button again. Thanks for all of your help.

[bryanj]

You have a UK model switch, always helps to give full info and where you are