Does anyone know of any mods, such as pipes, silencers.

 

A few years ago I went into a snowmobile dealer and asked about go-fast parts for my 1997 Arctic Cat Cougar 550. He told me if I wanted to go faster I should trade up and get a ZR500 or 600.

The point is, the money you would have to spend to make it go faster would be better spent buying something that's faster in the first place. Trade it in on a 500.

 

Not everyone has money coming out of there a$$, yes there are mods available, and a lot can be done for a better deal than getting soaked on trade-in by the dealer. RCR has a 414 kit that starts at a cost of around $400 us. For just under a grand Rick can set you up with a machine that will, I beleive he said, "beat a stock 425mag." So, if you want to keep what you have already spent in payments, save your money up and give Rick a call.

 

I thought it was pretty harsh when the dealer said that to me too, but in retrospect, if I consider the money I spent on the machine + Fox Shocks + Plastic skies + deep lug track + Black Magic clutch kit, I ended up spending more money on my Cougar than I would've on a ZR, and still didn't have a machine that was as fast.
If you simply want to improve the quad you have, yes, you can probably spend some money to get a bit more out of it.
If you actually want performance...dump it on some poor, unsuspecting slob and buy something better.
If you actually think that you can get some performance out of that Magnum, wake up.