A friend of mine has a 650 2005 AC, it has been under water before, but now runs fine except for cooling. I'm not sure too many details, but he said it was over heating and the shop could not find the problem. Keep in mind it's a hole in the wall shop that likely doesn't know whick side is up, but nevertheless I wanted to check here to see if there were any recalls, or common problems to check on this atv. Thanks for any help.
Oh yeah, the shops fix was to wire the cooling fan "on" all the time....time for a new shop!

 

Be sure that the radiator is clean inside and out. If there is gunk in the radiator, it could cause overheating, or if the fins are plugged up, then it will not cool correctly. If the radiator is clean, then look for other reasons, no circulation, or worse yet a cracked head or blown head gasket, if this is the case, there will likly be antifreeze in the oil, and/or bubbles in the antifreeze when you have it running with the rad cap off.

 

Right. If the coolent level is full, I am 100% positive the radiator fins are clogged. It happens a lot with these. Even if you look at it sitting in the ATV, you can't tell. But take the radiator off (a little bit of work, but not bad) and you will see how bad it really is.