This forum is now a year old but I had the identical problem on my sled that Popo700xc was having and I was able to fix it.
My sled is a 2013 Polaris Pro RMK 800. It died putting it into reverse and wouldn't start again. I was messing around with it and found it will start with the capacitor unplugged. I did test Ohms on the stator and it seemed normal. adjusted the TPS too. but after this it was starting normally with the capacitor plugged in. I thought the problem was fixed from adjusting the TPS but it wasn't long into the ride a few days later the same issue came back. I got stuck, shut it off, then it wouldn't start. it would still start with the capacitor unplugged but when the sled would be shut off it wouldn't start without it unplugged. Then it started throwing a engine code on the way home as well as flashing a low voltage icon on the screen. This is the code. (520215). later we learned the code was misleading. it indicated a short or open circuit to the EV solenoid. after testing this and that around the EV solenoid we decided to test the stator again. it's supposed to be 0.77 Ohms testing from the orange wire to the other orange wire. We found it now has an open loop on that faze. I pulled the stator and cut open the wire casing where the orange wires start into the windings and I found the the coil winding wire and one of the orange wires had arced apart resulting the open loop on the tester. I spliced the two wires back together and it now Ohms tests normal. we installed it back onto the sled and the problem is now fixed. the reason it was still running even with an open loop was because the electrical current was jumping across between the broken wire enough that it would still run. the reason it would still start with the capacitor unplugged was because it was drawing down the current and making the spark even weaker to the point of not firing. the reason why it tested good the first time I tested it was because the wires had not yet completely burnt through yet. but it was still burnt enough that it was starting to mess with the voltage. the reason why the wires were arcing through was because the connections are crimp connections and through all the heating and cooling the connection became lose and resulted in arcing. I hope this is some information that can help somebody. and here's some pages from the service manual that might help.
I have a 2016 Polaris 600 rmk, I have the same problem, only start with Capacitor Unplugged. Runs great with out Cap but no reversed.
What I have done so Far
1. New Stator
2. New VR
3. New Relay (Only one in this sled)
3. New Flywheel ( Why? Just in Case )
4. Check all stator Ohms, They all check ok
5. Check Orange (X) wire to from stator to ECM pin 21 and 26. ok
6. 6 volts to Capacitor (did charged Cap and check how slow in drain ( 1 min 12 vdc to 5vdc) I know I should get 14.6 VDC
7. 12VAC from Stator yellow (Z) Wires to VR, I have to idea what the voltage should be, the manual doesn't say
8. Brown (Y) to chassis ground ok
9. Charged Battery but she is not the best but will crank motor
I had some luck by using the pull cord with cap on and she would start but that a Russian roulette, don't work now, need to unplugged
cap to start.
Things I notice
- with cap off, a battery will flash on gauge only when accelerate
- with cap on the sled will have a small hesitation when punching the throttle, but not all the time
I'm running out of options, I know I'm missing something but what ?
If anyone of you here can give me something to check or something that I have missed I would greatly appreciated your help
Thank you
A Canadian guy
PS:
the reason why the wires were arcing through was because the connections are crimp connections
Where was this of the stator ?????