[John H]

Sorry...never mind. There's only so many things it might be and you have eliminated all of them I know of- battery, rectifier, stator, connections, harness.. so...I'm out of suggestions.

would you be willing or have the time at some point to get stator values from your machine so I can compare to mine before I buy and replace another part? Just thinking if your values are close to the same and you are charging perfectly well I could fully eliminate that.  if yours are significantly higher it would make sense that my values are simply too low.

[doug80638]

The thing about stators is that they produce a different voltage current depending the excitement of the coils, and that difference is determined by engine RPM. Higher RPMs, higher voltage (low amperage).

The regulator winds down the incoming voltage (which increase amperage) to produce a steady voltage (~14.2 - ~14.5) at any RPM with the potential to deliver more amperage at that voltage as RPMs increase. Any over supply of current to the regulator is dumped. So, even if you stator was marginally below spec, the regulator should still deliver a charging current.

The regulator decides how much amperage to dump based on the voltage level of the battery. The higher the charge on the battery, the more current is dumped, and vise versa. 

Stator failures are the result of shorts. You've ohm'd out all three circuits as open, so no shorts. And voltage production was steady at RPM, so it's doing its job.

You've bench tested two regulators to be good and still no charging current.

You've confirmed that the regulator is properly connected to the positive battery post. Check that the positive connection is tight to the regulator (inspect the grip tightness and that none of the plastic is melted)

The only thing left that I can think of is a bad regulator ground/connection.  Ohm that line to the battery ground post, and to the chassis. Check for tightness to the regulator just like the positive line.

If all that checks out, then Clark is correct. You've eliminated all the failure points.  A second set of eyes from a qualified mechanic may be prudent before spending time, money, and effort on a stator. 

 

[John H]

The thing about stators is that they produce a different voltage current depending the excitement of the coils, and that difference is determined by engine RPM. Higher RPMs, higher voltage (low amperage).

The regulator winds down the incoming voltage (which increase amperage) to produce a steady voltage (~14.2 - ~14.5) at any RPM with the potential to deliver more amperage at that voltage as RPMs increase. Any over supply of current to the regulator is dumped (dissipated as heat through the heat sink, which is why they get HOT!). So, even if you stator was marginally below spec, the regulator should still deliver a charging current.

The regulator decides how much amperage to dump based on the voltage level of the battery. The higher the charge on the battery, the more current is dumped, and vise versa. 

Stator failures are the result of shorts. You've ohm'd out all three circuits as open, so no shorts. And voltage production was steady at RPM, so it's doing its job.

You've bench tested two regulators to be good and still no charging current.

You've confirmed that the regulator is properly connected to the positive battery post. Check that the positive connection is tight to the regulator (inspect the grip tightness and that none of the plastic is melted)

The only thing left that I can think of is a bad regulator ground/connection.  Ohm that line to the battery ground post, and to the chassis. Check for tightness to the regulator just like the positive line.

If all that checks out, then Clark is correct. You've eliminated all the failure points.  A second set of eyes from a qualified mechanic may be prudent before spending time, money, and effort on a stator.

I appreciate the ideas and the guidance.  I will read back through all of this and formulate a plan.  I won't be able to do any further testing until Friday this week. I'm trying to figure out a way to temporarily eliminate the fuse wire and go direct to the battery but still power the rest of the items that use that supply. adding a heavy ga ground wire changed nothing but I can still check the green wire for continuity. One thing I keep going back to when I checked the stator values is the test between legs A-B A-C and B-C 2 (cheap) multimeters showed .8 ohms a 3rd meter (also cheap) showed .2 ohms.   spec is .5-1.5 if meter 3 is correct Mag coil resistance is too low. Again, not sure if it's enough to cause issue.

[doug80638]

I removed the part about heat. That's old school. The newer units use mofsets which produce less heat and regulate excess voltage more efficiently as I understand it.

[NMKawierider]

If I get a chance I'll check mine. They just opened up our forests and gearing-up now to go this Friday for a week or so.

Just use a T-tap or quick splice connector on that 12v wire. Leave it in place and run the extra straight to the battery. That way you can remove it later if necessary and seal-up the cuts with liquid tape.

[John H]

I have been all through this wiring looking for some fault somewhere.  I jumper the re/white wire and still only get 12+ volts I get that at the battery, at the fuse, after the fuse and at the distribution block that the fuse wire goes to.  I finally decided to just order and install a new stator.  As you all predicted, it was no help.  in fact, the new stator has worse voltage values than the stator I replaced. additionally, I now have an oil leak and assuming my gasket slipped during re-assembly. this is all very demoralizing.  I have owned this since March and have only put 65 miles on it.  going back to the voltage regulator.  I purchased the regulator for any zforce 800 from 2016-2019.  it also is used on the 2020 u-force 1000 model # 0800-177000-10000   the parts catalogue actually calls out part number 0800-177000-20000 for the 2020 800 ex. Does anyone have any idea what the difference could be between the 2 models? the part number for the 2020 and 2021 models is over $400 the other can be found for $40 and up. the proper part number is not available anywhere that I can find. its on backorder I'm wondering if it's simply a matched unit and won't work without the proper part number.  incidentally, if I hook up a battery charger to the battery, while it's running I get about 14v at the battery, at the distribution block after the fuse and on the dash screen. pull the charger and it drops right back to 12+v  static voltage on the battery is 12.8v.

[NMKawierider]

That's very distressing....it just can't be so complicated. Stators and rectifier/regulators and matched to systems either with or without power steering...ie you either have a 350 watt stator or a 500 watt stator... as far as I know, at least that's how it was a couple of years ago. Did you ever re-direct that trigger/output wire straight to the battery?
I see yours does take the  0800-177000-20000 regulator and the cost now is $502.00. Wow...I think I would talk to RM stator or Rick's about an alternative.

[John H]

That's very distressing....it just can't be so complicated. Stators and rectifier/regulators and matched to systems either with or without power steering...ie you either have a 350 watt stator or a 500 watt stator... as far as I know, at least that's how it was a couple of years ago. Did you ever re-direct that trigger/output wire straight to the battery?
I see yours does take the  0800-177000-20000 regulator and the cost now is $502.00. Wow...I think I would talk to RM stator or Rick's about an alternative.

I talked to RM stator today and they don't believe there would be any internal difference.  They suggested a part number I could use of theirs, it's a direct replacement for the uforce 800 and replacement for the part number that most of the other units use.  I put in a regulator that lists the as a replacement for the same part number and get no change in voltage.  I called a CFMOTO dealer and they looked for a superseded part number and did nto see one.  I talked to their tech writer and they did not know if the internals for the regulator would be different. I checked the voltage right out of the regulator by piercing the wire and I get the exact voltage. as the battery is getting. the trace wire was no help either. I would not mind tearing it back apart to fix my oil leak if I knew I had it fixed otherwise.  I guess I can be confident it's not coming back apart for a new stator because both gave similar values so it's not my issue. 

[NMKawierider]

Out of curiosity, has this engine ever been over heated?

[John H]

Out of curiosity, has this engine ever been over heated?

I could not say for sure.  I bought it used with 1100 miles on it.  while I used it, it has not.  Update, I talked to Curren Rv.  They called someone with CFMOTO and they claim the resistances are different within the correct part number rectifier. I just don't know enough about it.  RM stator thinks their part should work. The RM stator part is $109 I can get the correct part number from Curren in about 3 weeks from China at $460 ish.

[John H]

just a thought, I checked it out when the cover was off and did not see anything obviously wrong, but can something go wrong with the rotor that spins around the stator?

[NMKawierider]

just a thought, I checked it out when the cover was off and did not see anything obviously wrong, but can something go wrong with the rotor that spins around the stator?

Yes, the magnets can loose their magnetism..and that happens from either contact with the stator, impacts..like being dropped or..overheated. That's why I asked about ever being overheated. But the output voltage should be very low if that's the case..lower then it is I would think. Still, it's a possibility. 

[doug80638]

If you are getting proper voltage out out of the stator, the problem is going to be the regulator, a bad connection/ground or a broken wire.

Sorry you went through the cost and aggravation of replacing the stator.

[NMKawierider]

I forget...after all this did we ever try a new and correct rectifier/regulator?

[John H]

I forget...after all this did we ever try a new and correct rectifier/regulator?

I replaced the reg/rect with a unit that is called for on the 2016-2019 800 models and the 2020 u-force models.  I did not use the correct part number one for the 2020 and 2021 models.  RM Stator believes their model will work properly and there should be no internal difference.  One supplier who says they asked CFMOTO said they said there is an internal difference in the rect/regulator.  I ordered the RMstator model and I'm waiting for it to arrive.  they said I could return it if Its not helping. After that, the only thing left is to buy the proper model number rect/regulator and pay the $500 ish dollars.  That one I will be stuck with.  I'm planning on removing all the wires that feed the distribution bar that go to the trailer wiring and winch. I'm also going to pull the aux fuse so there is no possible way anything is using power except for the normal running of the buggy.  I again checked continuity of all the wires last night and I checked again to be sure the primary frame grounds were tight.