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Discussion Starter · #1 ·
Hi all,

I am having trouble getting a friends GPZ started, the bike was bought as a non runner, but was told it ran before it was partly stripped and the project started.

I have sorted out the wiring to the best of my ability (wiring is not my strong point) I have got the bike to spin over but now I cant get a spark, I know the plugs are fine as i've tested them on my ace, I have also tried a different igniter box that I know works which didn't help & all fuses are fine.

One of the wires going to each coil is live, the other seems to be dead.

Any suggestion will be great,

Thanks
G
 

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From what you've said, my vote goes for a bad trigger coil.

A lot of older bikes (or older design) use a floating-ground system for the coils, as in one side is always energized when the key is on, and the ECU/cdi box fires each coil by momentarily completing the ground side of the circuit.

The trigger coil(s) are typically inside the mag side engine cover. There's usually a little magnet on the flywheel that they read. Bikes can have anywhere from 1 to 4 depending on the ignition design. I'm going to guess yours only has one. When the magnet whizzes past the pickup/trigger coil, it generates a little pulse of electricity that "triggers" the CDI to fire a specific coil. If this coil is bad, or not connected, you will get no spark.

The service manual gives a spec for the ohms across it's 2 wires. Check that out. It's typically a fairly low value, like 2-4 or 4-8 ohms or something.
 
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