Inspecting and repairing electrics

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The internet is a rumor mill. It’s got rumors about everything, even my ZN. The internet rumor mill says that the ZN’s coils are marginal, at best.

Way back when this project was began, one of the first things I did was to go through the ZN’s electrical system—wires, connectors, joints, splices, whatever—and clean whatever I could get my grubby paws on.

electrical-2The electrics were in good condition, actually very good condition especially for a 30+-year-old bike. Everything was still together and functional. Even better than that, the wires were unmolested, except for a few minor type modifications to the OEM equipment.

I’m no electrician, not even vaguely close to it. In fact, I don’t mix well with electrics. We’re kind of like water and oil.

So this may be a good time to do some quality control on my work. A good place to start would be the ignition coils.

The ignition coils carry the 12 volts from the battery to the volts used to spark the spark plugs in the ignition. They’re important and this is what I did to test the ignition coils for input voltage.

  • Make sure the battery is fully charged.
  • Remove the fuel tank to access the coils.
  • Set the multimeter to VDC (Volts, Direct Current) or DCV (Direct Current Volts) with a range of 20.
  • Turn the run/stop switch to the “Run” position and turn the key to “On” position.
  • Touch the multimeter’s red probe to the post on the coil where the red wire would connect.
  • Touch the multimeter’s black probe to the negative terminal on the battery or a good ground on the frame.
  • electrical-1The multimeter displays the battery voltage at the ignition coil connection, depending on how much current is drawn by other items on the same circuit.
  • If the multimeter displays voltage down around 8-9 volts, then my cleaning job was not up to par and many other electrical connectors need to be re-done.

The ZN’s voltage consistently showed 11.4 volts when using a good grounding point on the frame. I’m sure better and more efficient ignition coils have gone to market since 1984. The coils on my ZN are fine and in no need of replacement no matter what the mill has rolled out.

I’m already working on repacking or replacing the bearings and checking the brakes which has been labor intensive with temps in the high 80s along with soaring humidity. But, with the passing of every day, this bike is getting closer and closer to being road-worthy.

Next: Lubricating a motorcycle

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