Topic: 1971 CB750 speedo wiring

[lash]

Bought a set of wires for my speedo/tach gauges from Yamiya and the speedo has an extra black and yellow wire into the gauge that doesnt hook up to anything. Any ideas what they are for?

[Kevin D]

Guessing now: speedo switch for the Japanese market "you're going too fast" lamp.
I didn't see black/yellow in Jonesys compilation of wire colors in the FAQ.
http://forums.sohc4.net/index.php/topic,1012.0.html

EDIT
I went to the Yamiya site and found this 7 wire harness, presuming that's what you have, and seeing unusual bullet connectors inside the speedo. I can't make out the wire colors on those 2, but guessing black and yellow. Also noticed a reference to a "dash valve", and item 12 lamp in the exploded view. WTH is a dash valve?? I think it's the too fast lamp.

[lash]

Thats exactly what I received and I think you are probably right about the "speed warning" light but there is nothing in the gauge to attach them to. I thought the speed warning mechanism was external to the gauge.

[Yamahawk]

Hmmm... I am thinking the original Japanese market speedometers might have had a 'switch' in the mechanism that would trigger that dash warning light inside the speedometer, for the dash light, and perhaps that hooked to the mystery wires...
Charlie

[lash]

I thought the thing in my last post was what generated the signal for the light. It looks like it threads onto the speedo on the bottom and the cable threads onto it, with the wires connecting to the wires coming out of it..

[Kevin D]

I thought the thing in my last post was what generated the signal for the light. It looks like it threads onto the speedo on the bottom and the cable threads onto it, with the wires connecting to the wires coming out of it..

Never seen one. What are the wire colors? Got a red lamp on your triple tree or triple clamp?