My daughter sunk our 2015 500 in muddy water. Go ahead and laugh, its ok.  Anyway, we were miles from the trailer, so I drained the air box, pulled the spark plug and blew the water out of the cylinder. I knew there would be some water in the oil, but decided to try and drive it back anyway (you can laugh again, its ok). I know I should have just got a tow the whole way. Well went about two miles and it started to smoke and cough. Shut her down and got a tow the rest of the way in.  What happened was the breather pushed watery oil into the air box enough for the intake to suck some up and smoke.  Got it home and drained the oil/water, put in fresh oil and some sea foam, cranked it and it fired up and idled for about 3 seconds, died, and would not fire again.  Cranks fine, has spark but wont fire. The efi trouble like blinks steady/constant. I know it is supposed to bink patterns for codes, but its just steady blink. 

Next, I left the battery unhooked overnight.  Tried again the next day, and it started and idled fine for a full minute(no smoke ), then did the same thing. But at least I got the new oil w/seafoam cycled around so I could drain that again. New air filter and more oil filters will be here tomorrow for a few more oil flushes.

So now that y'all got the laughter out of you system, I could use some advice:
1. Anyone know what the steady blinking EFI light means?
2. What else should I be checking to get it to keep running.
3. Is there anything else I should be checking for water besides the air box, oil, and gas?  Surprisingly I didn't see any water in the gas tank, but I suppose i should drain that and start fresh anyway.

Thanks in advance.

[2015 Z Force 800 53/Trail EPS]

Drowning a machine is no laughing matter...and I am so sorry it happened to yours. Running one with water in the oil is also no laughing matter..as it is a death sentence for the engine...especially the rod bearing(s) and oil pump. It also plays hell on the stator and rotor making shorts between the two. Even if you do get it running again it will likely be short lived. So sorry.  The light is probably from the O2 sensor or Mass air flow sensor being contaminated by the water..or just water in some connectors some where. The manual does explain how to make it blink the code. Do a compression and leak down test to see how the rings are and if the valves are leaking. Hot valve stems warp when hit with cold water...then they start binding in the guides. 

Yea, Im trying to stay upbeat about it so my daughter doesn't feel bad.  Hoping I can revive it enough to last through deer season just to drag a couple deer. Then I can tear it down over winter.  It only has 600 miles on it is the sad part.  It came from Polaris where it was a comparison test machine, and then sat in their test fleet for 5 years.  I see there is a crate motor available but its $3.5K. I'm only into this one for $2K (part of a $6K package deal with a Hisun that I got $4K back from). So I still wont be out of line if I put parts or a motor in it.  We will see. Im just not very familiar with these modern machines with OHVs and EFI and EPS systems.  Never to old to learn though.