I have a 2014 800 ex with 850miles on it what should the valve lash be in inches ?
Thanks

Download the manual if you haven't already. The conversion is .03937 per mm.
Intake .06-.14
Exhaust .11-.19

so with those ranges, what is the recommended set point?  in the middle of them?

Flip

with a cold engine I would go to the loose side a little bit, when it heats up the gap will close some.

I also go to the higher side if I can. Just make sure your  still inside the tolerance. I think by having the gap  on the larger side, it give you more room if the valves stretch more later.