Ian,
Your description is very vague, but your cooling problem is simple. First,
there are probably 2 water pumps as most generators are fresh water cooled.
So the first question would be what pump? I assume it is the raw water pump,
because somehow you detected that there is no water flow. If so, it is most
likely a rubber impeller self priming sea water variety. These are driven by
belts. Is the belt broken? Is there blockage in the sea water inlet, like a
plugged strainer? You know, the tank thing with a removable cover that the
water hose connects to from the pump. If not those, perhaps the impeller is
burned out because you ran it dry? I don't mean to be condesending, but your
question indicates you are not a tool person. If that is so, perhaps a
mechanic is in order. On the hunting issue, that is most likely a governor
issue, which will be part of the fuel injection pump. Although there are
adjustments for this type of a fault, I assume it once ran correctly, if so,
this indicates that something changed, like mechanical wear, so a detailed
inspection should be performed BEFORE any adustment is made, but if you are
not a tool person, definitely hire a mechanic.
Steve

"Ian Taylor" wrote in message
...
All,
I have an Onan genset in my '86 searay 340. It looks like the cooling pump
is not pumping water, and the genset is overheating an shutting down after
a couple of minutes. What is involved in changing this pump? Does anyone
know of a place of the web that might offer directions?

Also, the generator "hunts" causing the voltage to fluctuate greatly.
Anyone know how to fix that?

Thanks
Ian