29-02-12, 10:59 AM
I think you're probably spot on with that diagnosis Griff.
It's certainly well worth checking the battery voltage is being regulated before installing a new CDI.
I've not been impressed by the electrics on the two Kawasakis I've had. Quite apart from the poor quality wire they used, both suffered ignition problems:
The GPZ305 used a magneto to provide a high voltage to the CDI: this coil packed up after a few years... I got the generator rewound by an incompetent company called Electrex as I couldn't afford a new one. Even once they'd got it right that coil gave up after a few thousand miles. Eventually I built a small circuit to generate the 130V pulses needed which ran for the rest of the bike's life.
My GPZ500 started having intermittent ignition problems when it was still under warranty: high rpm would provoke it, but not if the engineer from the dealer was riding it... I ended up having to diagnose it myself. After checking the CDI itself was OK (by making a variable pulse generator to simulate the pick-up pulses) I found it was the pick-up coils themselves producing such a high voltage at high revs that it was overloading the input to the CDI. Some back-to-back zener diodes solved the problem.
It's certainly well worth checking the battery voltage is being regulated before installing a new CDI.
I've not been impressed by the electrics on the two Kawasakis I've had. Quite apart from the poor quality wire they used, both suffered ignition problems:
The GPZ305 used a magneto to provide a high voltage to the CDI: this coil packed up after a few years... I got the generator rewound by an incompetent company called Electrex as I couldn't afford a new one. Even once they'd got it right that coil gave up after a few thousand miles. Eventually I built a small circuit to generate the 130V pulses needed which ran for the rest of the bike's life.
My GPZ500 started having intermittent ignition problems when it was still under warranty: high rpm would provoke it, but not if the engineer from the dealer was riding it... I ended up having to diagnose it myself. After checking the CDI itself was OK (by making a variable pulse generator to simulate the pick-up pulses) I found it was the pick-up coils themselves producing such a high voltage at high revs that it was overloading the input to the CDI. Some back-to-back zener diodes solved the problem.