I was getting a mean decel pop at 7000'....not sure how the X would handle 10,000' without some jetting changes.....lol
next ride will have EFI, then I'll be searching for some elevation.....:d
4-strokes seamed more sensitive that day. We actually turned around because they were getting saucy.
Mine was low on power and soggy, but nothing serious (2-stroke).
We ride normally around 4500-6800 ft in the foot hills.
The view was pretty amazing though!