yep some 550 fanners had huge overheat issues which Polaris never really rectified. As stated above lots of info on net. do some reading I am not sure which years were affected but I thought it was around 2000.
the 550 was a completely different animal than the 488. The 488 was bulletproof.
The last three links I have posted above are written by people describing multiple failures of these engines on machines which have been manufactured prior to 2004. Apparently after 2006 Polaris began using nickasil cylinders which seemed to improve the situation to some level.
From what I read online I would not be so quick to say that the 2000 model was reliable. In fact it sounds like the opposite.
The main problem was oil line routing.
The line was too close to heat and the line either melted or the oil boiled, either of which caused a seize.
Longer lines routed farther away from the engine seemed to solve the problem.
Appreciate the comments... seems to be 50/50 on how good the machine is. I have had mine for three years... it's in top shape... i only put about 300 miles on it a year. Currently it has 3800 miles on it.
I too have heard bad things about the fanners. I was in the market for the same sled but Liquid 500 - 600 and had a real tough time finding one, well at least finding one I could afford. Personaly I've always had the notion that if you take care of it and don't beat the ever living crap out of any motor it should last.