GPZ 750 wiring

notgoodwithnames
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Re: GPZ 750 wiring

28 Sep 2026 18:20

#928007

F64 wrote:

put your red probe on the black wire that has none and push the starter button..

voltage?

Still none

1983 GPZ 750

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F64
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Re: GPZ 750 wiring

28 Sep 2026 18:22

#928008

your switch is bad

take a small wire and jumper both black wires

does the starter turn?

81-KZ440-D2.
Louis Dudzik's GM HEI ignitor conversion installed 2015 s3.amazonaws.com/gpzweb/Ignition/GPZgmHEImod.html
Motogadget m-unit blue installed 2017.
LIC, NY

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notgoodwithnames
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Re: GPZ 750 wiring

28 Sep 2026 18:25

#928009

F64 wrote:

your switch is bad

take a small wire and jumper both black wires

does the starter turn?

It sure as shit did, what a great end to a 9 hour headache. I'm sure it's gonna be an absolute bitch finding an original replacement

1983 GPZ 750

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Re: GPZ 750 wiring

28 Sep 2026 18:26

#928010

your switch may just be pitted.. you might be able to clean it

81-KZ440-D2.
Louis Dudzik's GM HEI ignitor conversion installed 2015 s3.amazonaws.com/gpzweb/Ignition/GPZgmHEImod.html
Motogadget m-unit blue installed 2017.
LIC, NY

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notgoodwithnames
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Re: GPZ 750 wiring

28 Sep 2026 18:29

#928011

F64 wrote:

your switch may just be pitted.. you might be able to clean it

When I get home from work tomorrow I'll disassemble it and hit it with a wire wheel. It looked pretty clean and worked not but a few months ago, but I did have one of the solder connections fail and I redid it so maybe I fucked something up when I did that. I'll hopefully have a post by this weekend with it riding, I bought the bike in May with the intention to ride it up to Barber this year so real crunch time goin on right now

1983 GPZ 750

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Re: GPZ 750 wiring

28 Sep 2026 18:41

#928012

Well, what's good is that you know the issue.
Let us know what you find when you get the switch apart.

81-KZ440-D2.
Louis Dudzik's GM HEI ignitor conversion installed 2015 s3.amazonaws.com/gpzweb/Ignition/GPZgmHEImod.html
Motogadget m-unit blue installed 2017.
LIC, NY

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H1Vindicator
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Re: GPZ 750 wiring

30 Sep 2026 06:23 - 30 Sep 2026 06:24

#928059

.. the Clymer manual states ...

just in case. there are a couple of 750-4 fsm pdfs floating around the internet. should be linked here on KZR. one has a yellowish cover with color wiring diagrams. the other is black-&-white.

Last edit: 30 Sep 2026 06:24 by H1Vindicator.

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notgoodwithnames
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Re: GPZ 750 wiring

01 Oct 2026 14:48 - 01 Oct 2026 15:24

#928100

Well everything is together and I went to go start the bike just now, really weak spark I thought it was the ignition coils but now I'm suspecting the igniter box. Any advice on replacements?

1983 GPZ 750

Last edit: 01 Oct 2026 15:24 by notgoodwithnames.

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bound
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Re: GPZ 750 wiring

01 Oct 2026 17:31

#928104

Did you actually test the ignition coils to be sure that they aren't the problem? It could also be your spark plugs or caps. I wouldnt go assuming its the igniter until you've gotten all of the more susceptible items out of the way. Do you have good voltage going to your coils? If you have a service manual it has nice testing procedures for this that I would check out.

1982 KZ1000M2 CSR
1983 KZ440D5 LTD
1985 GPz 550A2

Craig

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Re: GPZ 750 wiring

01 Oct 2026 17:49

#928106

Ignition coils have 12v at key on and drops to 7.5-8 when hitting start, both ohm out at 2.4, 470 out of the pickup coil. I went through all the tests in the Clymer manual and the only thing I haven't done which it recommends is to try a known good igniter

1983 GPZ 750

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Re: GPZ 750 wiring

01 Oct 2026 19:13

#928109

I prefer factory manuals if possible. Here is how to test the igniter if you wish.

1982 KZ1000M2 CSR
1983 KZ440D5 LTD
1985 GPz 550A2

Craig

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Re: GPZ 750 wiring

01 Oct 2026 19:48

#928111

I'm getting ohm readings that seem to be way off from everything in that chart. The 4 and 5 pin which it says should have infinite with everything also has resistance with multiple other pins. I found another one local that I'm gonna pick up tomorrow morning so fingers crossed I get to actually ride the damn thing for once instead of using it as decor

1983 GPZ 750

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