Topic: Cb750k2 No spark, wiering help needed

[Odin]

Hi again

I thought i had my cb750k2s electrical system figured out now, but for spark test it failed.

I have signal from the ignition points, they seem to open and close like the should when i run continuity test on the wires up at the coil. I suspect its something to do with the kill switch, did some tests but ended up slightly confused.

is the black with white stripe that runs from killswitch to coil supposed to have ground? mine seems to have ground all the time, no matter what position my switch is in. If i read the wireing diagram, the black wire in the switch, should connect to the black with white stripe and turn it hot, so i find this a bit confusing.

Is there any easy way i can unhook or bypass the killswitch just to make sure its where the problem is?
Is there no hot wires running to the coil at all?

Thanks in advance for any helps and tips.

[bryanj]

Black is +12volt into kill switch, black/white is +12volt to coils with switch on. Ground is via contacts.

[69cb750]

If i read the wireing diagram, the black wire in the switch, should connect to the black with white stripe and turn it hot, so i find this a bit confusing.

The black wire is +12 volts, when switch is on black/white wire is +12 volts, check with volt meter.

Is there any easy way i can unhook or bypass the killswitch just to make sure its where the problem is?

Use a jumper from black to black/white to bypass switch.

Is there no hot wires running to the coil at all?

The black/white wire is +12 volts, check with volt meter.

[Odin]

Thanks

Ok thats what i suspected, i must have something wrong in my switch then since its no +12v coming out.

I will try black to black and white tomorrow just to see if i can get some spark then.

Down at the coils, the coilbracket mounts, are they supposed to be insulated or something? or doesnt this matter? i was looking at it today and since it looks like it will ground to frame via the coilmounting brackets i thought maybe the black with white was supposed to be ground.

Thanks again for ur help

[Odin]

Hi again

Now i got spark, and got the kill switch fixed, so thats working.

However, now i get spark arking from the front of the coil metal "ears" up to the screw that the bracket mounts thru in the frame.

The screw is a bit long so i can cut that down a little bit to avoid getting close to the hot coil ears, but seems a bit sketchy, am i missing something, special screw, rubber?

Thanks again for all ur help.

[69cb750]

Spark plugs arcing when attached to coil wire is good, any other arcing is bad, you need new coils.