dand11, I've never seen the shims that you are talking about, but it maybe possible that polaris has something simular on their quads. Definitly worth a look. My experience has been with snowmobiles, and I've never run in to any thing like that, but it sounds like a good idea if you want to limit top speed.

 

I've had my 325 Magnum for almost 9 months and have similar complaints about the top end of this machine. It is a heavyweight, to be sure, but a very comfortable ride. I have had no problems with my bike and am quite satisfied with it, except for the power, er, lack of power, that is...
I was wondering about the 325 owners here who have compared the 325 to the 500. I've sat on a 500 mag but have never drove one to see for myself the differences.
If you, as a 325 mag owner, had to buy another bike would you buy the 500 Magnum, and why.