2 & 3 no spark

[Bama704]

I am trying to get my bike to run, it did not when I bought it. Cylinders 1 & 4 have spark but 2 & 3 do not. I have brand new coils on the bike so I don't think that is the problem. Any suggestions on what to check next?

Bike is a 1977 KZ900

 

[Bert Jan]

Powerfeed to the coils and the signal wires.

Put power on the positive lead of the coil and negative to ground of coil. Connect the two signal wires. Check for spark while attaching/detaching the signal wires.

Spark? Coil ok. No spark? Coil dead.

Problem is electical. Swap the wires from the working coil to the non working and check for spark again. 1&4 dead now? Either points/cdi broken, positive lead broken, no earth on coil (did you coat the frame?? A coil needs ground to work..) or no signal from the signal wires.

Report findings and good luck!

 

[goldy]

Running standard ignition? First place to look is the ignition points, then condensers/ wiring.
Let us know what you find.

 

[Bama704]

I had checked the points and did some small adjustments, the problem was traced back to an electrical problem. The coils were fine but there was some corrosion at the terminals. Once cleaned up the bike now fires and runs on all 4. Thanks for the help.