Hi
well i would put money on it being the thermostat i have replaced
them a lot they tend to get stuck open so just pull it and look at it
. and make sure u bleed the system good.
Brad
paraprosracing.com
I have yet to see a thermostat in 660 rhinos.
check to see if water is moving when cold, keep cap open for this. if not, the tang that feeds the water pump broke off.
bleed system like mentioned, but it is up on the outlet water neck near driver, not down on the water pump. 8 or 10mm wrench I believe
head gasket is possible
fan not coming on is possible