72 CB500 Four K0 No Spark troubleshoot?

[gioventures]

Okay, so after rebuilding the engine for my 1972 CB500 Four and re-instslling the wiring harness and electricals, ive come to find that the wires arent producing spark to the plugs. Head lamp, dummy lights, turn signals, electric starter all fully functionining and fine. All plugs are brand new, condensors were replaced and are new, original points still on but contacts were sanded down and make full even contact, original coils, original wires and wire caps, original stator, brand new Yuasa Battery filled with new electrolights and charged at 13. Starter works, engine kicks over perfectly but still no spark from open ended wires when grounded. If some one who knows these electricals well and has dealt with the same problems can guide me through a step by step process of elimination in order to trouble shoot the source, it would be very helpful and appriciated. Id like to know which components I should test for first and in order and I need exact numbers to look for when using the Multi meter. Hope some one can help! :-\

 

[Bert Jan]

The coils get their main power from the black/white wire. When you turn the key, main power from the red wire (battery +) is connected to black. Black is main power when key is "on" position. Red is always hot

first, check with the meter if there is power on the black/white wire. If so, your loom is ok on the power part. If not, find out why.

secondly, locate the yellow and blue wire. Those are the signal wires from points to coils. They basicly give the signal to the coil when to fire. Often these are swapped, resulting in misfire/not running.

As you have no spark at all and assuming there is power on the black/white wire feeding the coils, its probalby earth. Did you powdercoat the frame?? The metal studs on wich the coils are connected to th frame need a good clean solid earth connection to the frame. If you are insure of that, take a spare wire and wrap it around the metal part of the coils. Attach thr other end to the negative battery terminal.

 

[Bert Jan]

Edit: black and black/white are essential the same wire but black/white is dedicated to the coils. They are connected to each other further down the loom.

 

[jvandyke]

don't know if helps at all but it's cool to play with
http://oldmanhonda.com/MC/wiring500.html
don't forget to play with the switches and stuff

 

[gioventures]

Thank you guys. I will start to chase the wires hopefully this weekend once i have some time on my hands and let you know what i have determined to be the cause. Yes the frame was powder coated and I had the problem of no ground due to it before, so i made sure to grind off enough of the coating down to bare metal in order to get a proper ground. This was further tested by a wire wrap and coninuity test. Are there any numbers I should look for in particular to know if the coils or condensers are good while testing them?