I'm looking for input on how high of an altitude, if any, that I should start to be be concerned with operating my 500HO as-is from the factory. Anyone have experience operating a stock 500HO at ten thousand feet above sea level?
Thanks, Outlawd

 

Since most of our time on the Polaris is spent at 3500 to 7500 feet above sea level, is there an "all around" jetting solution for us?
Thanks, Outlawd

 

I took my new 450es to Wy mountains(1000 ft) last summer. It ran fine (with 87 octain) as long as I didn't get on it full throttle. At high speed it stumbled and ran poorly. The second tank of gas was 92 octain, boy what a difference! Took it back to Co. Elk hunting in Nov. (-9* every morn), hunted at 8500', again with 92 oc. it ran great. The gas made the difference for mine.

 

Hopefully this will help you. The charts I have and have used successfully for my own stuff say this..............And remember
THESE ARE APPROXIMATIONS (not gospel) for stock applications. What you should do is jet it for the "middle ground" of your riding altitude, So here is what I can tell you.
For every 1000 ft you go above your factory setting (Usually 0 to 1500 ft above sea level) you need to reduce jet size by 2 percent. Remember, this is a percentage of the factory jet size. So by my calculations if you are riding at 5000 ft. that is 3500 ft over the factory setting. So a reduction of 5 or 6 percent would seem safe. So if the factory jet was a 155...(example I dont know what yourstock size is) minus 6 percent of that (which would be around 9) that should give a proper jet size of 146 (This can also be checked by "reading the plug" to see how it is burning.)
Then you can fine tune it with your needle clip.
I usually start in the middle position and work up or down from there. Also if you err on the safe side (rich) you wont burn it down.
These are general starting points but with time and patience in your tuning you will get optimum performance and with that optimum pleasure from your quad!! Good luck !!

Trailboss450