Took my bike out over Labor Day to see how it would run on the trails with all the mods. Started out at 6000 ft with no problems but when I got up to 9000 ft the bike wouldn't idle and was very sluggish when climbing. I adjusted the idle to around 2.5K rpm and the bike ran fine with the exception of a lag in when first accelerating. The bike has a K and N filter, 120 main, stock pilot, N1TC needle/3rd slot from top, Full Muzzy, 2.5 turns on fuel screw, and crankcase drilled. My head pipe has a blueish tint but does not backfire when letting off the throttle. I only got 46 miles before going on reserve after during the test.....

Based on what I have read the bike would run richer at a higher altitude, so I am considering going to the 2nd slot on the needle, and changing the fuel screw to 1.5 turns. Any suggestions.....

 

You will also have to change the main jet if you used that much gas in 46 miles you are WAY FAT[] Some of my friends that ride around 1000 to 3000 ' took there stuff to utah and went from 5000 to 11,500 ' Most of them would not even run .... only the ATV 's with EFI ran fine. Another quick fix for day rides in high altitude is just take off your air box lid while your at that elevation. That will make a big difference , it sucks when you almost need 2 carbs for mountain climbing