I have a 2004 polaris sportsman 500 ho- just bought it a few days ago. I was driving it and thought it wasnt getting enough rpm cause it didnt have as much power as my dads quad which is the same quad. I put the quad in neutral and revved it as high as it would go,and it only got 5000 rpm. I did the same test on my dads quad and it will get 7920 rpm. The new one is nearly 3000 rpm less- any ideas on what the problem could be?