I wanted to buy a big locomotive, and so was looking at previously owned SWT's. I didn't want to part with $8 g's so began looking at other sleds. Aha! I found a nice 2002 Polaris 800 RMK with the 156"x2" track in Kenai for $3500.00. From the photos it looked brand new; this could be explained by the 1800 miles on the odometer.
My BIL went over to look at it and it was nice. Guy fired it up, sounded great. So I transferred $3500 from my account to his and it arrived here within a few days as his buddy was driving to Anchorage and dropped it off at NAC. $835 later it's here. I had it put into my truck for the ride to the Pol shop for a once over before I began tooling up and down the river. About 30 minutes later the shop manager and mech calls me, "could you come over"? Uhhh...okay. I drive over and he tells me to look at the pistons. He had the VES valves out to clean. I look in the holes....four cornered. Mag side pretty bad. I tell him to do a top end on it and go home. About 45 minutes later he again calls, "you need to come over and look at this". I so did NOT want to look at "this". I get there and he has the jugs off. They are trashed. Grooved up both, and both piston skirts cracked, mag side is gone. It went down into the motor then pieces went up and out the exhaust, but not before embedding some in the head.
Why could the machine run and sound good? Because the rings were all still intact and it was holding enough compression to run. Long and short: if I had asked for my BIL to check the compression I do not think it would have been over 100psi in either cylinder. It should be around 135psi. I could have saved some money. Like $110 for a head, $575 for jugs, $1100 for a rebuilt bottom end, and $300 for a piston kit. Not to mention labor. So check the compression on those previously owned machines, pull the valves to take a peak, and if they don't have valves then pull the pipe to check those pistons. It could save some heartache.