I run a P1000 with Mattracks UR3 Plus tracks,
Mattracks | M3 Series ATV & Side by Side Tracks and it overheats. The issue is we offload at 3000' and travel to 8900' in 30 miles, running at 4000-5000 RPM with the speed odometer registering 40-45 MPH. However, the ground speed is 10-15 MPH due to the 3:1 gearing in the tracks. We are not getting enough airflow due to slow ground speed.
The Honda P1000 is designed to be air cooled and has the stock rear fan (puller) controlled by the computer for times at idle . We had issues with the computer not turning on the fan (or sometimes coming on too late), or turning off. By the time the 4 bar was lite and the yellow overheating light came on, we had already puked out the blue coolant. (so much for early warning).
Yesterday, I installed the fan override switch (purchased for the club store), a new pusher fan in the front and upgrade the factory fan to a higher cfm. Also added the second battery and have both fans on switches. With everything on the voltage drops from 14.2 to 13.1 and pulls 20 amps.
As for power lost, the higher elevation and heat will cause horsepower lost. These are great machines but clearly not designed to run Mattracks in the mountains.