I have a 1999 polaris super sport 550 and I found a 1999 polaris xc600 for 1500.00 I asked the guy if he wanted to trade and he said yes but I would have to give him 400.00 I went and looked at it it is in perfect shape except the engine didnt run very good he fired it up and it backfired alot and then it died and he couldnt get it started again he said it had a fouled plug it has 3400 miles on it and mine has 3700 miles and is in perfect shape it runs awesome. I was wondering if it would be a good trade. I am kinda scared of how the engine sounded though I wanted to know if I should do the trade or not.