my new project sled-Help!

Very new to the forum & thanks for having me.
i just bought a n 03 mountain cat that was switched from a carbed 900cc to an efi
the fella rode it for a bit and on a semi warm day's ride it went into idle mode, come to find the chip in the ecu fried. Searched around engine bay and found a busted ground wire. He figured it to be the reason. He bought a used ecu to ride with and did so for a half dozen rides but then rode on another semi warm day(40degrees or so) and 20 miles into it he idle moded again. He went straight to the ecu and found exact same thing. He gave up and sold it to me so i could play with it.
my initial thinking is a couple things. 1) voltage regulator is bad 2) stator is spiking. I tallked with a guy for a bit and he mentioned that regulators for efi's are more expensive b/c of the fact they do more--made me wonder if in the carb to efi swap they left the carb regulator and it is overloaded now and spiking thus burning ecu up?
its a bit wordy but i wanted to try and get as much info in as possible.
Anythoughts?
Oh yea i am in search of an 04efi 900cc ECU at this point. I will get the numbers and add them tomorrow. If anyone has a used one let me know. Might even look for a different regulator for an efi system just to make sure. If you have one of those let me knowalso!

Let me do some testing this weekend and i will get back to you!. I should make sure an800 ecu will work too?! Didnt think of that idea. Would i need the throttle bodies too or just the ecu? I am hoping the voltage regulator is the problem so i "know" prior to hooking up anothe computer for it to burn up.
it has to be something giving it a high shot of electricity since it is just one particular spot on the ecu the keeps melting down.
anyone heard of this problem?

getting a better picture

So i had a coversation with statorkev, he said that the voltage regulator controls the lights, hand warmers, etc. It doesnt control ecu. Also figured out that the stator failing would create less voltage not more.
how many grounds are there in the wiring harness? I am really wondering if there is a broken ground or a busted ground wire in the shaething??
i was told that an 800 ecu shouldnt work so i better keep her simple and just locate a 900 eu

Backing up a bit, it seems that when you want solid knowledge you go straight to the source. Call arctic cat and yes you can reflash multiple ecu units. Also got some insight as to potential problems.
VR is bad, maybe
servo is bad, maybe

This weekkend i am going to really look at wiring harnes and even do some dielectric just to make sure. Hoping i can test the VR but would expect i need it running a this point and that is a no go with fried ecu...

What are specs on an EFI VR and Servo?