Charging System Issues

I'm back after a short hiatus of small/no issues.
Current issue -
Bike will start (after charger has been hooked up) and run for a while. The other day it ran with no issues for 10 minutes, other times like today it only ran for a few minutes before dying at a stop sign. This has happened three times in the last two months.
The first time I rode the bike maybe a mile down a main street - Speeds 40mph or so. The bike starts to bog, like running out of gas, then eventually died when I pulled over (pulled the clutch). I figured it was a battery because I could not get the bike to crank afterwards, it would try and fail, until eventually no crank. I got a new battery AGM from walmart, put it in and the bike fired right up. I rode it home and parked it. I thought the issue was solved.

The second time mostly the same except I was smart enough to stay in the neighborhood. Same symptoms, the bike would start spitting through the carbs like I'm running out of gas. Pull over, pull clutch and it dies. Let it sit for a few mins, it wants to crank but eventually nothing. Walked the bike home.

Today, same symptoms. Riding down the street, starts to act like we're low on gas. Dies at a stop sign. It wants to crank at first but eventually gives up. I start walking the bike home, uphill :evil: , get sick of it and luckily the bike fires and runs long enough to make it home. I hooked a multimeter to the battery and it reads 11.3. I tried to start it - failed. now the battery reads 10.3. I have it charging now.

I am thinking we're dealing with a charging issue since the bike fires after the battery has been charged. I'm guessing the alternator isn't sending a charge back to the battery while riding? The bike's previous owner set up electronic ignition and I haven't touched any wiring except to swap batteries and hook up a horn. The manual suggests to test the rectifier and alternator so that'll be coming tonight but I am very green to any wiring issues. The manual mentions colors of wires but since the PO made changes I doubt I'll see the colors the manual suggests.

Edit - Upon further inspection. It would appear I do not have a voltage regulator on the bike. It should be connected to the green connector yes? My green connector is plugged in but no wires coming to/from. Moving onto the rectifier resistance.

One other thing that might be related - Some time last year I noticed that the ignition switch would start the bike as soon as I turned it to run, as in I don't need to hit the start button.

Ideas? Comments? All are welcome.

Thanks in advance for the support.

You said several times that it is like running out of gas. Maybe you are. A clogged fuel cap vent, a a paper fuel filter, or even a fuel line that is coming apart inside could cause the symptoms you describe.
There should be a regulator unless somebody installed a combo regulator rectifier at some point.

If you "think" it's the charging system why not go ahead and check it out. At a minimum charge the battery completely then start the bike up with a volt meter connected to the battery properly. See what you are getting for voltage into the battery and compare it to your service manual. You should find out right quick if the charging system is operating correctly.
Rick H.

Theres a chance it could be gas related. The bike sat over the winter and I've not emptied the carb bowls. I did put stabilizer in the tank before winter. If it were fuel related, that would not explain the bike not having enough umph to crank after it died though would it?

Yessir Rick, that's the plan. Waiting on the green light from the charger.

TexasKZ wrote: You said several times that it is like running out of gas. Maybe you are. A clogged fuel cap vent, a a paper fuel filter, or even a fuel line that is coming apart inside could cause the symptoms you describe.
There should be a regulator unless somebody installed a combo regulator rectifier at some point.

I have a Shindengen 12v Regulator Rectifier SH230-12. Is that a combo unit? I have one brown wire coming from the green harness/plug that joins three yellow wires going in.

A regulator rectifier is a combo unit >> the rectifier & voltage regulator were separate parts on some early KZ models but later they were combined into one unit, hence the name. If still unsure, post the wire colors of the unit.

Ok so I started the bike when the batter was full (13.4V)

4000RPM w Lights off - Readings all over the place. The gauge bounced from .3 to 15.2 and everywhere in between. If I had to pull an average together it was 12-13 range. The book would indicate that if the reading is under 14 volts then the Regulator or the Rectifier or the Alternator is bad, gee thanks.

I pulled the green connector, the only wire going from the green connector to the regulator/rectifer is a brown wire. *Note I mentioned earlier that my start button seemed to be "always on" (as soon as I turned the kill switch to run the bike started). Once I unplugged the green connector (brown wire) this was no longer the case. I had to press the start button to actually start the bike* Again testing at 4000RPM the meter settled in between 12.8 and 13V. The book would indicate that the regulator is probably good, but the rectifier or alternator is bad. Since I have a combo regulator/rectifier I guess I'm back to it being either that unit or the alternator.

Something else of note possibly - When I turn the bike off, I can hear a "winding down" sound from the left side of the bike. I know that is where my starter/stator/alternator is located so maybe its getting worn out?

Edit - I've found some options for replacement of stator and rectifier on z1parts and z1e. Any recommendations on which to go with? The one from z1parts is about 60% more expensive.

Also something to note - I have a 75 z1b engine but a 76 kz900 frame. One of the stators says it is for a z1 and that it'll work with a kz900 but I'd have to cut off the leads to the oil pressure switch. Sound right?

Conspiracy wrote:
One of the stators says it is for a z1 and that it'll work with a kz900 but I'd have to cut off the leads to the oil pressure switch. Sound right?

It could be wrong but...

An early oil pressure Switch has a bolt on ring connector




A later oil pressure Switch has a female bullet connector

Scirocco wrote:

Conspiracy wrote:
One of the stators says it is for a z1 and that it'll work with a kz900 but I'd have to cut off the leads to the oil pressure switch. Sound right?

I could be wrong but...

An early oil pressure Switch has a bolt on ring connector



A later oil pressure Switch has a female bullet connector

I'll go out and take a look to see if I have anything that looks like that.

ok here is maybe the same thing? i don’t have hoses near mine though.

I think the hoses are for an oil cooler perhaps.

Rick H.

Rich is right, i put oil cooler hoses on.