Fried Stator

I have an '83 KZ1100L1 LTD with a fried Stator. I've been troubleshooting the charging system all weekend using the ElectroSport troubleshooting guide located in the Filebase of this site. I have found several corroded connections and cleaned them up and had the system charging....... kinda???

I pulled the stator after noticing that one of the windings was a little different than the rest and now I know why.

After removing the stator I noticed that one winding had been really hot and melted all the varnish off the windings on one post. it turns out that this winding is the one that the resistance is a bit lower than the rest.

I replaced the positive and negative battery cables and cleaned every connection in the charging system with sandpaper and contact cleaner.

I intend to order a electrosport stator but I'm not sure whether or not to order the RR. It seems to be working according to the troubleshooting guide but I'm not sure if it needs to be replaced to work correctly with the new Stator. I really don't want to spend another hundred dollars if I don't have to but I want the charging system to be right when I finish.

What do you guys think???

I already have more in this bike than I can ever get out of it but I really don't plan on selling it.

Thanks for your help,
Tony T

The Electrosport fault finding chart is fine but here is what I would do if I owned the bike... first, to check the stator, I would disconnect the connector that connects the stator to the regulator rectifier and start the bike. It will start/run off the battery fine as long as the battery is charged. I would take my multimeter and since you have three wires coming from the stator that carry AC, I would check the AC voltage on each pair. I honestly don't know what to expect on your bike model (I don't much work on the J motor stuff) but I would guess 60 VAC on each pair. IF I had a reasonable number coming off each pair (somewhere between 50 and 70 VAC as a guess), I would declare the stator good. Having seen burnt winding... well I would just replace the stator with a used stator from a donor bike (see eBay) and give this test a shot.

Once you are getting AC from the stator at a sufficient level, hook the stator back up to the reg/rec. Put your multimeter in VDC scale (20 VDC or 50 VDC) and put the probes on the battery terminals. Since power comes out the reg/rec and powers the battery as well as going to the main fuse, you can check the reg/rec output by starting the bike and noting the DC voltage at idle. A normal voltage will be ~ 12.3 - 12.5 VDC. Now rev the engine to 3500-4000 rpm and note the voltage. It should be ~14.5 VDC.

Since you have already tested and verified the AC voltage, if there is a problem, it will typically show up when you rev the bike. The reg/rec will either make significantly more or less than the 14.5 VDC at the higher rpm. If it does, the battery will either not charge as it should (lower voltage than expected) or you will fry things (higher voltage than expected). If the reg/rec puts out significantly more or less than the voltages I note, it is bad.

Of course, all this supposes that wiring contacts are clean and secure. Make sure the battery is fully charged and healthy before attempting tests. The easiest and cheapest way is to fully charge using a SLOW, low amp trickle charger and then test with a HYDROMETER. These things look like little bitty eyedroppers with colored balls in the body. You put a small piece of hose on the dropper part and suck in some battery fluid from each cell. If all the balls FLOAT, then the cell is good. If some float, it is marginal to a greater or lesser degree and if you have a cell where the balls don't float, the cell is DEAD. You can buy a hydrometer for less than $5. Check your battery. Then check the connections to the battery. Make sure the ground is clean and real secure. Make sure the wire connecting the positive anode to the starter solenoid is clean and secure. Make sure the connector between stator and reg/rec is clean/secure. The best way is to open the connector and shoot it with electrical contact cleaner (autoparts store) and dab the pins with dielectic grease (autoparts store). Make sure that the white or white red wires coming off the reg/rec connecting to the main fuse and battery are cleaned and dabbed with dielectic grease. Once you have done this stuff, it is really possible to start isolating electrical component problems.

I would do this stuff before spending too much on electrical bits.

first, to check the stator, I would disconnect the connector that connects the stator to the regulator rectifier and start the bike. It will start/run off the battery fine as long as the battery is charged. I would take my multimeter and since you have three wires coming from the stator that carry AC, I would check the AC voltage on each pair. I honestly don't know what to expect on your bike model (I don't much work on the J motor stuff) but I would guess 60 VAC on each pair. IF I had a reasonable number coming off each pair (somewhere between 50 and 70 VAC as a guess), I would declare the stator good. Having seen burnt winding... well I would just replace the stator with a used stator from a donor bike (see eBay) and give this test a shot.

I have a new battery (heavy duty gel type) and I made sure it was charged overnight before I started my test.

The way I tested the system on Sunday was as follows.
1. Connect the volt meter on 20VDC scale, start the bike. The reading at idle was 12.33 and 12.5 at 4000 rpm.

2. Unpluged the connector under the side cover and tested the 3 yellow stator leads. I had a reading of .9 ohm on two of the wire pairs and .5 on the other (both way wrong). Then I checked each lead to the engine case and had 1.1 ohm on two and 1.0 on the other (again, wrong). There should be no reading to ground according to the service manual.

3. Removed the stator and did a visual and found the wires without varnish on one pole shorting them together.

At that point I knew I had a bad stator so I did a quick test on the RR following the instructions in the manual. It tested good.

I went ahead and changed the battery cables and cleaned everything in the charging system just to make sure I had good connections once I replaced the stator.

wiredgeorge raised a few questions for me so I put the stator back on the bike and tested it again with the bike running. 26-27 volts AC on two windings and 18 volts on the other. My service manual says 50 volts is the goal so I'm way short of that.

The RR could still be bad because my test were static based resistance test, which brings me back to my original question. Should I change the stator and regulator as a set?

The reason I ask that question is because the Electrosport stator is said to have higher output at idle and while riding. Since I've not used one of them before I thought it may heat the regulator more than the stock stator did. Any power that is not used is dissipated as heat and I didn't know if the Electorsport RR had better cooling and components due to over 20 years of technology since my bike was built.

I know that no one can tell if the RR will fail faster or not but I was hoping to get a few opinions of people that have used them to help me make up my mind. I hate playing the guessing game and not having my facts together before I make a decision to spend money :pinch:

Any of you guys have an opinion that you'd like to share?

wiredgeorge, thanks for your help. I have printed your response to my question and added it to my electrical section of my service manual -- good stuff!

Stone Cold, your reasoning seems right on. The stator seems to be shorted to ground. With an aftermarket stator that claims more power, you'll probably be safer with an aftermarket reg/rec. But, it would be nice to hear from someone who has done the upgrade to the new stator.

On a side note, even when a charging system is totally dead, the DC voltage of the battery will rise slightly at higher RPMs, about a few tenths or half a volt or so. That's because the ignition uses less power at higher RPMs.

Post edited by: loudhvx, at: 2007/03/13 13:23

O.k! The weather here is wonderful and I REALLY want to ride my bike so I ordered the parts yesterday.

I ordered the Electrosport stator and regulator/rectifier. My thinking is better safe than sorry. Since the same company makes both they should work together really well.

I've gone to a lot of trouble to make sure all the connections are perfect and ready to go so I was just being cheap at the wrong time --- at least that's what my wife said.

This bike is my new daily driver and I really don't want to be stranded on he interstate with a dead battery.

I plan to make a trip next month and don't want to breakdown 150 miles from home. It's not like you can just walk into a parts house and pick up the parts so fix it now.

I try to carry the stuff that breaks with me (clutch cable, throttle cable, bulbs, extra relay for the ignition and stuff like that) so i can repair the bike where it sits. I learned that with points type ignition :woohoo: I've had to adjust points many times 1000 miles from home and if you don't have a spare set the old ones will be pitted beyond repair, at least that's my luck

Thanks for all your help and be safe,
Tony T

O.k.
As a follow up to my earlier question I want to let you guys know how everything turned out.

I ordered an Electrosport stator and reg/rec to replace my defective units.

The stator is a straight forward remove and replace except I eliminated a few connections along the way and ran the yellow wires all the way up to the reg/rec connector (eliminated 3 connections, 3 less to worry about). The wires on the new unit were plenty long enough and it comes with a wire sheath to run the wires in. I just made it like a separate harness.

I also replaced the regulator/rectifier while I was at it. The reg/rec has fewer wires that the stock unit and they are different colors. My old reg/rec had 3 yellow wires, a brown, a black and a white. The new unit has 3 yellow wires, a black and a red. Electrosport says the brown wire is not needed with their reg/rec.

So now the tricky part. The three yellow wires were in the correct spot on the connector as was the black wire. The red wire on the new unit would have connected to the brown wire that comes from the switch but it needed to go to the white wire that goes to my fuse block so I moved it to the correct place on the connector and plugged it up. This reg/rec does not have a switched wire going to it. It works very similar to a Delco 10SI with a self-exciting regulator where it starts working when the stator windings pass through a magnetic field.

Anyway! This setup works GREAT. The old system really didn't charge at idle even when it was work correctly and was lets just say anemic even at highway speeds. The New system charges at idle and really well at highway speed. The bike even runs better because I'm getting higher voltage at the ignitions coils. All in all it's well worth the $200 and pocket change that it cost to do it.

One other thing I'd like to warn of; the new reg/rec is thicker than the old one so you will have to have new bolts to make it work. Don't use to long of a bolt or it will rub the bottom of the battery.

Good luck and happy charging

Tony T

Tony, You might want to put your location in your signature. Heck, you might be my neighbor and I have several good used reg/recs. Your reasoning was spot-on... The basic question is not the stator. It is fried. When troubleshooting a stator, your problem will be either the magnet part or more likely the windings. In your case, you SHOULD assume the windings due to observation of poor voltage levels and the fried wires. The second part of your reasoning as to whether to pick up a new reg/rec or chance the old one basically comes down to your ability to afford a new one vs the inconvenience of a failure. My feeling is that the old reg/rec could well be OK and I WOULD check it with the new stator installed. See if you get 14.5 VDC at 4K rpm and even if you do, swap it out and use it as a spare for the Electrosport. Like I said, I have several extra. Oddly, I have never had one fail on a Kaw but have had several fail on Suzukis and they are probably made by the same vendor in Japan... hehe Good luck with your riding!

Nice job Tony!

Like WG said, failed Kaw reg/rec combos are rare, but piece of mind is always good.

BTW, from what I've seen, the Suz reg/recs are inferior tto the Kaw designs.

Hi wiredgeorge and loudhvx,
I have added my location to my signature so you guys can see where I'm from.

The old regulator tested good with the meter but I didn't want to chance it. I'll stick it back on today and do a test with the new stator. If it's good on the bike I'll add it to the tool bag along with the other "emergency" reapir items I carry (I hate sitting on the side of the road :blush: ).

I'm very confident in my abilities as a mechanic but it's nice to be able to bounce stuff off you guys. Ya'll have been a huge help and I can thank you enough.

Humbly,
Tony T

Where can the Electrosport units be purchased?

Where can the Electrosport units be purchased?

Where can the Electrosport units be purchased?