Best I found was also 2011. Rich Daly from Dynoport put it on the Dyno for Snowtech. Pulled 152hp on heat soaked engine that day. With Dynoport y pipe/pipe/can it pulled 159 Hp with 105.7 ft/lbs of torque. I haven't seen any Dyno runs of the 12 or the 13 two injector 800 RMK.
American Snowmobiler put a '13 800 on a Dyno this year and it pulled 142 Hp. It was not an RMK, I think it was a 800 rush.
IMO it would be very interesting to take 3 800 s with broken in engines, ride them hard for a few hours in mtns, pull them into shop right away and Dyno all 3. Who cares what the numbers are, I am interested in the difference between Cat/poo/doo; especially the torque number.
Somebody on Snowest Has to have access to a Dyno and pull off something like this. Snowest should do this as a part of their deep powder challenge every year. Dyno all 3 at elevation after punishing these engines in the steep and deep. Bone stock.
All that said. I sure wish I was riding right now instead of dreaming if riding.