welcome to QuadCrazy. The problem you have would be that your shift linkage needs to be adjusted if it goes into low and reverse your problem would most like be that it is pretty simple to fix. When you try putting it in high gear does it sound like the gears are grinding a little? Check the oil level two in the transmission case
1999 Polaris Sportsman 500 popping out of high gear! 
Re: 1999 Polaris Sportsman 500 popping out of high gear! 
Linear Mode
