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Help with Kz750 charging issues

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13 Mar 2021 13:40 #844877 by F64
Replied by F64 on topic Help with Kz750 charging issues
do you have another battery that you can swap in?

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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  • JohnLuke
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  • 1982 KZ750N Spectre
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13 Mar 2021 20:18 #844888 by JohnLuke
Replied by JohnLuke on topic Help with Kz750 charging issues
I bought a new battery today. When it comes in I’m hookup to test it.
The following user(s) said Thank You: F64

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16 Mar 2021 18:51 #845031 by JohnLuke
Replied by JohnLuke on topic Help with Kz750 charging issues
New battery did nothing.

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16 Mar 2021 18:55 #845032 by JohnLuke
Replied by JohnLuke on topic Help with Kz750 charging issues
New 801 cell antigravity battery. New ricks Motorsport stator. New sh775ab r/r. Nothing. Still starts and charges at 12.30-40v. When I rev it it gets close to 12.90v or so. But isn’t it supposed to be close to 14v? I’m so freaking frustrated.

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16 Mar 2021 19:14 - 16 Mar 2021 19:15 #845033 by Kaylinator
Replied by Kaylinator on topic Help with Kz750 charging issues
A resting battery is 12.6V

1978 KZ1000-A2
kzrider.com/forum/11-projects/613296-1978-kz1000-a2-barn-find

1978 KZ400-B1

2022 Z900RS SE
Last edit: 16 Mar 2021 19:15 by Kaylinator.

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  • JohnLuke
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16 Mar 2021 19:18 #845034 by JohnLuke
Replied by JohnLuke on topic Help with Kz750 charging issues
Right. My bad. This is with the bike off. It’s still charging though. I just got it in the mail. Probably not fully charged.
Attachments:

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16 Mar 2021 19:34 - 16 Mar 2021 19:52 #845036 by F64
Replied by F64 on topic Help with Kz750 charging issues
I'm still thinking you may have a wiring issue.
If your battery were low, the voltage regulator would be running the voltage up around 14.5V at 4k rpm.
So charging the battery to 13.6V won't really help bring your charging voltage up.

Try the tests I mentioned on the first page.

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
Last edit: 16 Mar 2021 19:52 by F64.

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16 Mar 2021 20:17 #845039 by JohnLuke
Replied by JohnLuke on topic Help with Kz750 charging issues
That has to be it. I’m gonna try and drive her to work on a Saturday and check the wiring then. I’ll do what you said on your first post. I know that my regular rectifier has 12v and a good ground. Maybe one of my three phase wires is shorted or something. How would I diagnose that?


I’m pretty sure I needed the battery anyway because my battery has been completely drained and apparently that’s detrimental to the battery. Plus I read somewhere that if the volts drop to about 9v on cranking it’s bad. Which the old battery did.

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16 Mar 2021 20:33 #845040 by JohnLuke
Replied by JohnLuke on topic Help with Kz750 charging issues
I’m honestly thinking it’s one of the 3 phase wires. That’s what imma check first. If I have 25-40v on the stator then I’ll look somewhere else.

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16 Mar 2021 20:50 - 16 Mar 2021 21:15 #845041 by F64
Replied by F64 on topic Help with Kz750 charging issues
start the bike
idle
meter on AC V
We'll label each stator wire as #1,#2,#3
backprobe the bullet connectors between the stator and the reg/rec
probe #1,#2 note voltage
probe #1,#3 note voltage
probe #2,#3 note voltage

raise rpm to 2k
meter those connections again

raise rpm to 4k
meter those connections once more

your AC V should go up as the rpms go up
they should be similar between each wire combination

turn off bike
put meter on resistance
disconnect stator wires from reg/rec
keep one probe on stator case(ground)

measuring the wires coming from the stator
probe #1 note resistance
move to probe #2 wire note resistance
move probe to #3 wire note resistance
all readings should be infinty or open or you have a short between the stator and ground.

Your old rectifier/regulator have 6 wires or 5?
And how many wires does the new reg/rec have?

Your new charging system will be .5V lower than the lead acid.
Rick's maxed the reg/rec at 14.0V for lithium ion instead of 14.5V for lead acid.

3:13 explains the voltage difference between the lithium and lead acid.

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
Last edit: 16 Mar 2021 21:15 by F64.

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17 Mar 2021 04:03 #845051 by JohnLuke
Replied by JohnLuke on topic Help with Kz750 charging issues
Excellent!!! This explains it very well. I’ll go through that process once I get the chance after work or something and note everything I. I believe that my old connector was 6 wires. 3 yellow. A red and a black. And I believe a brown. I left all those connections unplugged and wired my new charging system in. Then I wired the new system. 3 yellow wires from the stator to the R/R. One black wire from the negative battery post/common ground. And one red positive wire that has direct 12v from battery/ switched 12v. Really it’s just a constant 12v. So what am I missing?

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17 Mar 2021 04:45 - 17 Mar 2021 04:46 #845053 by JohnLuke
Replied by JohnLuke on topic Help with Kz750 charging issues
What imma try and do is film each step if possible and send it here so you can see what’s up. Here is a test video. 
Attachments:

    IMG_0435.MOV

Last edit: 17 Mar 2021 04:46 by JohnLuke.

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