Pulse generator wire question

[tommyoneleg]

My first post here, I have a 1980 cb750f, just bought it a little bit ago, has a sidecar on it. My pulse generator was bad so I put a dyna 2000 on it, everything is running but I need to find the "tach-input wire" on the bike.

On the attached picture the black wire goes to the engine but I don't know what it does and the green wire I have no idea about. I know I should have taken some pictures but when you get working you just forget sometimes and I have looked all over for a diagram but none found. If anyone can point me in a good direction so I am not walking in circle, a little joke.

thanks
Tommy oneleg

 

[SenseAmidMadness]

The little black wire in that diagram goes to the oil pressure light switch, which is on top of the transmission part of the crankcase, to the right side of the starter motor cover. The green wire goes down under the chain cover to the neutral indicator light switch.

 

[RuncleUckus]

The little black wire in that diagram goes to the oil pressure light switch, which is on top of the transmission part of the crankcase, to the right side of the starter motor cover. The green wire goes down under the chain cover to the neutral indicator light switch.

Do you know if the yellow and blue wires that go to the spark units have polarity? I'm currently rewiring my 80 cb750c. I have black, green, 2 yellow and 2 blue. I know the yellows go to one unit and blue goes to the other but I don't know if I can accidently wire them backwards

 

[SenseAmidMadness]

It's not "polarity" per se but what I remember is that yellow is one coil circuit and blue is the other. Reference your wiring diagram to make sure. If you get them backwards your spark timing will be wrong.

 

[RuncleUckus]

Yea I know the yellow wires goes to the unit for 2/3 and blue goes to the unit for 1/4. I added the wiring diagram I'm following. I just need to know if I wired the 2 yellow wires backwards going into the spark unit for 2/3 does it matter? Or does it act more just like a switch where polarity doesn't matter and its just on or off