CA 77, 1967 dream coil questions

[Hoytd]

On a 1967 dream, CA77. Bike wouldn’t run, intermittent spark on right plug, no spark on left. Had power to coil, so I ordered a new coil. Installed new coil and have no spark on either side. Using test light, I have power in on both sides of coil, is this as it should be?

[Muddy]

G'day Hoytd

I'm unsure how you have diagnosed the no spark issue, but did you check the spark plugs, plug caps and connection to the plug leads - they can be troublesome. Coils can give problems, but would be less common than poor plugs, plug caps and plug leads.

If you are referring to both the small diameter electrical cables in and out of the ignition coil, then you will see around 12 volts on either of these. One cable, the black cable on the bike's wiring harness, will provide 12 volts from the ignition switch to the coil. There should be no power when the ignition switch is turned off. The other small diameter cable coming out of the coil (green on the bike's wiring harness) will go to the ignition points (contact breaker) and condenser. You should see 12 volts on this cable when the ignition is turned on.

The ignition points (contact breaker) is just a simple switch that opens and closes as the engine rotates. For good reliable spark, the ignition points must be clean and set correctly and the condenser must be in good condition.

Good luck.

Regards

Muddy

[Hoytd]

Thanks Muddy, I’ll let you know when I get back to it

[Hoytd]

Thanks Muddy, I’ll let you know when I get back to it