We've got a few U800s and C800s that have had an issues with starting.  They start right up initially but quit after a second.  Do the same thing again and it quits 1/2 the time.  The other 1/2 the time it will start and run rough.  Like it's running on 1 cylinder.  You can rev it up and it feels like that cyl comes and goes.  Most of the machines run better on there own when they warm up but one runs rough even when warm.  Any body else have anything similar happen?  Thanks

[2015 Z Force 800 53/Trail EPS]

May be a fuel pump or water in the filter. Check the pressure and volume. Also check the valve lash.

I'm thinking too many different machines to be water.  Definitely will check the the fuel pressure and valve tho.  Thanks.

I haven't started mine in a few days, I'll start it tomorrow and see if it's OK. Did it start doing this when it got cold?

Sorry, it took me a few days. I started my CForce and it's running fine so I don't think it's the cold. Is it only your 800's doing it or the 500's too?