[NMKawierider]

Did some more looking and reading. Looks like I might be right about totaling all three readings to get at or better then 200 vac

[glenlivet]

Just a random idea... In quads and small motorcycles charging issues have often been traced to an imperfect ground negative between the battery and the regulator. Introducing a 10 gauge or so wire between the battery negative right on the battery to the body of the regulator or to the negative out of the regulator has made poor or non charging machines jump right up to 13.9-14 volts. Bad grounds are sneaky.

[John H]

Did some more looking and reading. Looks like I might be right about totaling all three readings to get at or better then 200

I test all 3. each are are right around the 66v so 198v  I would assume that is a minimum and thus it could be right at spec if not just a touch low.  Would assume not low enough to cause only 12.55v charging at the battery.  I think I will add the ground and see what happens. The stator may be on its way out but not cooked yet. I tested the VR/Rectifier and its working as it should But I'm going to test again before putting it back on.

[John H]

Checked the rectifier again. I don't understand the table in the service manual but looking online it seems I should have .55 volts checking foreward bias on most rectifiers.  I have that 1 way but only .12 the running the other way and OL backwards. Not sure if that means I need a VR or not?

[John H]

I found a Video specific to the Mosfet Rectifier.  I get good values all through all the checks so back to assuming the Rectifier is good.  Can I check Voltage out of the Reg/Rectifier before going to the battery? Meaning if the Stator is hooked up on the Stator side, can I unhook the Pos and Neg leads form the Regulator and start the buggy and take a reading right out of the regulator? Thinking is, if I was getting 13+ volts at the regulator, I would know I had an issue further down the line at the fuse or in the wiring before it got to the battery.  Although. I do understand I'm right at the bottom end of the Stator Spec. with 198V.  That was jsut sort of an average as the voltage was bouncing around with the person holding the gas was not super steady at 5K RPM. 
Thoughts?  Just replace the Stator?

John

[NMKawierider]

The regulator requires the battery being tied-in so nope, can't read the output without it in the system...far as I know. The stator voltage is below the minimum...although not by much, it is. Is there one phase that is very much lower then the other two or are they all about the same? Regardless, do check the chassis ground to the engine case as well as all other connectors and main fuse holder for any high resistance connections. Then if all is good I would just replace the stator cause if 200 is the minimum, normal is probably more like 225 or about 75 each set.. or more I'm thinking. The 2015+Kawasaki Brute Forces with Power steering, the total of all three can be as much as 270 vac I see. These should ..IMO.. be within the same range.

[John H]

The regulator requires the battery being tied-in so nope, can't read the output without it in the system...far as I know. The stator voltage is below the minimum...although not by much, it is. Is there one phase that is very much lower then the other two or are they all about the same? Regardless, do check the chassis ground to the engine case as well as all other connectors and main fuse holder for any high resistance connections. Then if all is good I would just replace the stator cause if 200 is the minimum, normal is probably more like 225 or about 75 each set.. or more I'm thinking. The 2015+Kawasaki Brute Forces with Power steering, the total of all three can be as much as 270 vac I see. These should ..IMO.. be within the same range.

All 3 legs were basically identical. all right at that 66V range.  I was not sure how to test the crimps near the main fuses under the drivers seat.  DO you have a good way to test voltage before the fuse and after? do I need to peel back the insulation or pierce the wire with a point probe?  I think you are right about each Leg likely being closer to the 75V range based on what I found for a Polaris General spec.

[doug80638]

Did you ohm the stator lines.  The resistance should be the same across any two at a time.
They should all read open when connected with ground.

[NMKawierider]

The regulator requires the battery being tied-in so nope, can't read the output without it in the system...far as I know. The stator voltage is below the minimum...although not by much, it is. Is there one phase that is very much lower then the other two or are they all about the same? Regardless, do check the chassis ground to the engine case as well as all other connectors and main fuse holder for any high resistance connections. Then if all is good I would just replace the stator cause if 200 is the minimum, normal is probably more like 225 or about 75 each set.. or more I'm thinking. The 2015+Kawasaki Brute Forces with Power steering, the total of all three can be as much as 270 vac I see. These should ..IMO.. be within the same range.

All 3 legs were basically identical. all right at that 66V range.  I was not sure how to test the crimps near the main fuses under the drivers seat.  DO you have a good way to test voltage before the fuse and after? do I need to peel back the insulation or pierce the wire with a point probe?  I think you are right about each Leg likely being closer to the 75V range based on what I found for a Polaris General spec.

I just pierce it with a sharp probe and seal it afterwards with some liquid tape. I was also reading in the Kawasaki manual that there are three things that can cause a low reading on the stator. A short within a coil or coils, an open or break in a coil's winding or loss of magnetism within the rotor...and that can happen from several things including impacts, contract between the rotor and coils or excessive heat for a prolonged period. If you do end up going in, take a close look for any contact points and check all the magnets are the same strength. 

[John H]

Did you ohm the stator lines.  The resistance should be the same across any two at a time.
They should all read open when connected with ground.

Yes.  I did do the ohm check between all 3 legs without it running (static) all were .8  Spec is .5-1.5 Also did the check from leg to ground and all were OL. 
Thanks for the suggestion. 

[John H]

The regulator requires the battery being tied-in so nope, can't read the output without it in the system...far as I know. The stator voltage is below the minimum...although not by much, it is. Is there one phase that is very much lower then the other two or are they all about the same? Regardless, do check the chassis ground to the engine case as well as all other connectors and main fuse holder for any high resistance connections. Then if all is good I would just replace the stator cause if 200 is the minimum, normal is probably more like 225 or about 75 each set.. or more I'm thinking. The 2015+Kawasaki Brute Forces with Power steering, the total of all three can be as much as 270 vac I see. These should ..IMO.. be within the same range.

All 3 legs were basically identical. all right at that 66V range.  I was not sure how to test the crimps near the main fuses under the drivers seat.  DO you have a good way to test voltage before the fuse and after? do I need to peel back the insulation or pierce the wire with a point probe?  I think you are right about each Leg likely being closer to the 75V range based on what I found for a Polaris General spec.

I just pierce it with a sharp probe and seal it afterwards with some liquid tape. I was also reading in the Kawasaki manual that there are three things that can cause a low reading on the stator. A short within a coil or coils, an open or break in a coil's winding or loss of magnetism within the rotor...and that can happen from several things including impacts, contract between the rotor and coils or excessive heat for a prolonged period. If you do end up going in, take a close look for any contact points and check all the magnets are the same strength.

great info.  I will look it over.  I'm going to check the wires before the fuse and after to see if I'm losing voltage there.  I will also run the extra ground form the battery to the Rectifier.  if no help, I guess I will order the stator.
I really appreciate all the suggestions from everyone.  I have not found too many posts about actual failed stators in the Z series. Was really hoping for a 2 bolt 2 plug rectifier to be the culprit.

John

[doug80638]

My apologies for asking a question that had already been answered. Senior moment!

It's pretty clear the stator is not the problem. It ohms out and produces voltage within spec, or at least so close, that I could imaging the difference being variability in the multi-meter or RPMs. Couldn't hurt to try a second meter and redo the test just to verify the theory. The regulator will produce charging voltage at way less than 200v total (just lower amperage).

I would replace the regulator long before replacing a stator performing as you have described. Regulators are fairly cheap, much easier to swap out, and more likely to be the problem.

Know anyone with a similar machine willing to lend you their regulator for a test?

[John H]

My apologies for asking a question that had already been answered. Senior moment!

It's pretty clear the stator is not the problem. It ohms out and produces voltage within spec, or at least so close, that I could imaging the difference being variability in the multi-meter or RPMs. Couldn't hurt to try a second meter and redo the test just to verify the theory. The regulator will produce charging voltage at way less than 200v total (just lower amperage).

I would replace the regulator long before replacing a stator performing as you have described. Regulators are fairly cheap, much easier to swap out, and more likely to be the problem.

Know anyone with a similar machine willing to lend you their regulator for a test?

I actually did use a 2nd meter. I brought one from home because the one I keep at the cabin sits out in the shed all the time, did not know if hot and cold would affect after years and wanted to do a basic charging test.  the Meter from home showed even less charging than the 12.55V it was showing on the meter that I keep at the cabin. it showed 11.8v  Then I did the static test with both meters and one showed  .8oh and the meter from home showed only .2oh (out of spec)  SO I went to the neighbor and borrowed one and introduced a 3rd. It showed the same .8v on all legs.  All 3 showed OL when testing to ground.  I was doing everything I could do to be sure I had good info.  I will say none of the 3 are very high end.  2 are DB electric and they read the basically the same the 3rd with the lower reading is a Sperry. all 3 measured the same running (dynamic voltage) right around the 66v per leg.  Maybe the voltage reg gets hot and starts dropping voltage.  I do know someone with a Uforce 1000 but they don't bring their machine up and it's for farm use so they likely won't want to take it down for testing.  It would be interesting to see if anyone else has a ZF8 and could do a dynaminic test to see what their stator is putting out. if it was around 235 or more it would be pretty clear what I need to do.  It still could be dropping voltage at the fuse connection.

[doug80638]

Let's see if I can summarize this:

The battery load tests good.
Sitting voltage of battery is 13.4 volts when fully charged - perfect.
Battery voltage with engine running is ~ 12.5 - indicates no charging is taking place.
   I'll bet it drops further if you turn on the lights or induce other loads.
The stator bench ohm tests within spec, no shorts,  and is putting out sufficient voltage on each leg.
The regulator bench tests OK.


The next step is to take a voltage reading at the regulator Positive wire.
Should be the same as battery voltage when engine is not running. 
If reading is not between 13.5V and 15V at 5000rpm, replace the regulator.
If voltage is above 13.5 at regulator, and not at battery, check the positive wire between the battery and regulator for breaks or bad connections. Check ground is clean and tight.

Assuming no voltage increase at the regulator ...

I've modified the original post here.

The regulator part number 2019 Z8 and earlier: 0800-177000-10000  $50-$70 (internet search)
The regulator part number 2020 U8 and earlier: 0800-177000-10000  $50-$70 (internet search)
The regulator part number 2020 Z8 and later  : 0800-177000-20000   $300+  Yikes!

I don't know the difference between the two part numbers, or why the Uforce is different from the Zforce in 2020, but if the plugs are the same between the two the older version should work. I would buy from someone with easy return policy if you go the cheap  route.

[John H]

Let's see if I can summarize this:

The battery load tests good.
Sitting voltage of battery is 13.4 volts when fully charged - perfect.
Battery voltage with engine running is ~ 12.5 - indicates no charging is taking place.
   I'll bet it drops further if you turn on the lights or induce other loads.
The stator bench ohm tests within spec, no shorts,  and is putting out sufficient voltage on each leg.
The regulator bench tests OK.


The next step is to take a voltage reading at the regulator Positive wire.
Should be the same as battery voltage when engine is not running. 
If reading is not between 13.5V and 15V at 5000rpm, replace the regulator.
If voltage is above 13.5 at regulator, and not at battery, check the positive wire between the battery and regulator for breaks or bad connections. Check ground is clean and tight.

Assuming no voltage increase at the regulator ...

$69 regulator at MortchMotor. Shipping will probably be around $25 - 3 to 5 days, DHL.
Amazon has some better deals on aftermarket regulators. Ebay too.

http://online.mortch.com/CFMoto-CF800cc-EFI-Rectifier-Voltage-Regulator-0800-177000-10000-High-Power

This is for 0800-177000-10000. Your part number may be 0800-177000-20000. I don't know what the differences might between the two, but if the plugs are the same, it should work.

Great summary.  I checked them and the shipping is $50.  the Amazon and Ebay regulators seem to be the lower power non EPS models.  How do I test the positive wire coming out of the regulator? Pierce the insulation and liquid tape it just like testing at the fuse?  I wish the Buggy was at home with me instead it's 2 hours away.