1- really down on power at 10-13K feet compared to sea level. I have a 2010 and 2014 850 XP’s. I have 26 and 27 inch tires on the machines and also have an EPI clutch on the 2010 as well as an aftermarket exhaust ( swamp series exhaust ) and the 2014 is very stock except for QSC clutch and 26 inch tires ( Kenda Bearclaw HTR II) .
2 – right gas to use ? 91, 87 or 85 octane ??
3- gas additives to deal with all the ethanol is this colorado fuel ??
4 Octane booster of ANY value ?
5 – Air Filters ? Any value at altitude ?
6 – 2014 850 XP – I installed a QSC clutch from Ryan in MN, great guy… I got a little stiffer spring and lightened up the keys to 57.5 Grams and it seems to be more responsive.
7 – Sparkplugs – I am running the laser NGK in both machines.
Any help from all you high altitude riders is greatly appreciated.