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Not a C-10 GPZ900 issues

killingbugs

Member
Member
I have a 1984 GPZ900 that I can not get to spark.
I have changed/checked trigger coils, swapped igniter with a C-10 (it run good with it)
Checked/swapped coils with the C-10.
Added SISF's Free Power for C-10's mod , cleaned all grounds, it has new battery.

Bypassed clutch safety switch, and side stand switch.
I have 12v at the coils, and when I crank the motor and use voltmeter on the trigger coils I show a change in reading.
Went front to back cleaning all connectors with contact cleaner and a toothbrush.

The "main relay" is warm with the key off. And when you pull it out or reinstall it you can hear it click.
I swapped other relays into the "main" position and they all do the same thing.
Fuse box/junction box failure???

Bought the bike after a long time sitting. Only has 4200 miles on it.

I have matches and gasoline, don't make me use them :mad:

 
Time to troubleshoot why that relay is energized with key off. Could be a short. Could be a bad ignition switch. Could be a failure in JB.


There won’t be a “this is your problem” answer from anyone here, because it will take hands-on troubleshooting. Pull out your wiring diagram, start tracing what energizes that relay, and eliminate them one at a time.


This is electrical 101 stuff. Basics. You just gotta do them. There is no shortcut.


I’ve said this before - these are simple machines, electrically, nearly identical to any car from the 50’s onward, except for the JBOX and electronic ignition (and the wiring is still very similar). The JBOX largely just concentrates a few relays you would find inline in other vehicles.


Study the wiring diagram, verify what the bike is actually doing. The answer lies there.






 
I once intended to use a GPZ igniter box on my C-10.
As I recall the 2 were not interchangeable.

Maybe, you need to go back to the original igniter?

Ride safe, Ted
 
Bikejunkie1013 said:
I have a 1984 GPZ900 that I can not get to spark.
I have changed/checked trigger coils, swapped igniter with a C-10 (it run good with it)
Checked/swapped coils with the C-10.
Added SISF's Free Power for C-10's mod , cleaned all grounds, it has new battery.

Bypassed clutch safety switch, and side stand switch.
I have 12v at the coils, and when I crank the motor and use voltmeter on the trigger coils I show a change in reading.
Went front to back cleaning all connectors with contact cleaner and a toothbrush.

The "main relay" is warm with the key off. And when you pull it out or reinstall it you can hear it click.
I swapped other relays into the "main" position and they all do the same thing.
Fuse box/junction box failure???

Bought the bike after a long time sitting. Only has 4200 miles on it.

I have matches and gasoline, don't make me use them :mad:

I know it begins sounding like a broken record... record... record,,
but if you dont have a factory FSM, better pend the mony on one, not a Clymers, or other, a true FSM.

swapping ZG parts onto your bike, isn't in any way viable, as the 2 bike differed in many hidden aspects. Especially when it comes to electrical wires, and the interconnects, to individual parts, like Jbox..

you have a relay that appears to be energized constantly, and will eventually drain your battery.. disconnect the battery, remove and recharge it, and have it on standby.
then, analyze and meter check the appropriate ares via the FSM specs, and methods, to find the fault.

the '84 GPZ's had a very basic electrical system, by modern standards... a C10 box wasn't designed yet at that point.

when you find the issue, it will be something you never checked, and will very likely be a very simple thing.. sorry, even tho I worked on GPZ's of that era, during that era, I can't "put a finger " on a specific..
 
I have the Clymers and the Kawasaki Factory manuals

The Ignitor for the 1984-1987 GPZ900 and the C-10 are the same part number 21119-1111

I contacted Larry Buck about the junction box, I may have to try another used one as new ones are not available for less then the price of a running GPZ

I have pulled the "hot" relay and only install it when trying to start the GPZ

I have looked the wiring harness over and don't see any obvious wear on the wrap.

I'm looking at a used junction box but they are the same age and look worse than mine.


 
getting in Contact with Larry is a good idea, he can go over your Jbox, and replace relays if needed....

The reason I made specific comments about "differences" in the harness and wires between the C10 and '86 era GPZ/Ninja models, is when I was fitting a gage cluster for my nekid bike build (COGZilla), I ended up using one from a GPZ, and it worked great, pretty much plug and play, and the speedo worked correctly also, but the GPZ has a "Voltmeter function button" on the gage, which allows you to see volts when it's pressed, also there is a "kickstand down" warning light power wire that i had to snip, as that particular wire on the gage connector, was mating with the clock power wire on the C10 harness side... so I have to assume there were more "differences" in wires than just what I saw, in the gage pod.

best of luck on the resurection,
 
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