Was gonna rebuild the waterpump, but thought first to check the thermostat, pulled off the housing on top of the motor and just a big hole!!! Do these things have a thermostat? Anyone out there have the cooling system a part before that may have some insight? All new to me here. Any help would be greatly appreciated.

Is it spewing Coolant from the overflow ???? Does it do it before you think the thing is even hot enough to be overheating ??? If so you have a blown head gasket no matter how many people are going to tell you differantly. Get it fixed right away don't believe me ask King Glamis.

go over exactly what its doing from cold to overheat. easy way to see if your water pump is working or air in the system is to start it from cold, if the red overheat light goes on within a minute or so and the radiator tanks are cold its an air pocket in the system, if that doesnt light up then start feeling the radiator tanks, carefully of course, if both sides warm up close to evenly then its pumping water, if one side is warm/hot and the other is cold then its not moving water. and like said above if its pushing water out the overflow its the head gasket, check the inner exhaust tip for white residue.

Theres nothing to rebuild in the water pump. Theres 1 seal and an O-ring, if its leaking there rebuild it. if not you need a head gasket most likely.

ive only had a water pump fail 2 ways. my brother didnt line the slots of the shafts up correctly putting the cover back on which pushed the shaft out of the snapring. the other was the decompression weight mechanisms failed a few ways, one was the tanged washer ear broke off, the other was the pressed pivot pin broke off and the decomp weight fell in the motor, said parts falling in the motor wedged between the slotted shaft and broke off one side.

660's do not have a thermostat... fi 700's do.

first thing i would do is check too see if the radiator fan is turning on.

secondly, carefully clean out all dirt and debris between the radiator fins.