Motorcycle Safety & Driveability: GPZ750 Ignition, kawasaki gpz750, wiring switches

Question
Kawasaki GPZ750 1986
My son bought it, and is difficult to start, it was when he bought it.Previous owner said it was bad.
I find the spark to all cylinders is very weak,wiring switches and plugs/leads all  test OK (I am an electronics engineer so have all equipment to test)

I now suspect the electronic ignition unit,or that both coils could be faulty,a new battery has just been fitted by me so have full voltage to ignition.Without fitting spares I cannot test further.The problem is no one seems to have any advice on the testing of these and replacements are very expensive,so have to prove what is faulty before ordering parts.
Any ideas?

Patrick

Answer
Patrick,

As you say, it's probably the EI unit, not the coils. The coils on the GPz bikes were very reliable, but the early EI units not so much. I'd locate a used one that's been tested (ebay or findmypart.com) and try that first. If you replace the EI and still have weak spark, then parhaps the coils are bad. Depends on how the bike has been cared for, too.

Of course, I have to ask the obvious question: How's the battery? If it's the battery that's been in the bike from the previous owner, I'd test it. A new one may be the easy fix. I've seen it happen before.

Good luck,

Bill Roberson