OK, I have searched the threads and not found exactly what I am looking for. I just purchased a 2012 Sportsman 400, and am setting it up for use primarily OVER 10,000 ft., in Colorado.
This is what I am in the process of doing. If anyone else has dialed in a 400 for high altitude use, please let me know if I am close here. I know it will take some additional fine tuning, but most of the time I live at 6,000 ft, so tuning will have to be done when I am in the high country.
1. Needle jet moved to 2nd slot (was in 3rd).
2. Fuel/air mix: removed brass plug, went all the way in, then 1 1/2 turns out.
3. Ordered two main jets, starting with a 147.5, can drop to a 145 if necessary.
4. Any change to pilot necessary? Recommendation?
Stock air cleaner, stock exhaust, no snorkel.
Now, fluids. I like using aftermarket, so don't bomb me for not using Polaris branded. I believe their is always an equivalent. These are what I am planning to use. If this is wrong, please let me know. Lots of opinions out there, but very hard to find FACTS.
Engine: Synthetic 0w-40
Xmsn: Synthetic 5w-20
Rear Diff: Synthetic 75-90
Front Diff: Synthetic Type F ATF... can use demand drive if this is not a valid equivalent. This was the hardest one to find another option for.