have a 1980 volvo aq125b with a 270 sterndrive new t stat and raw water impeller .is it possible to do an in boat test of the circ.pump? boat is overheating
No tests for that pump, I doubt it's your problem anyway. Does your raw water pump water when the engine runs? Is the exhaust manifold plugged up? Is the heat exchanger clean?
When exactly does it overheat? In the water, on plane, in the driveway on muffs?????
The only thing that could happen to the circulation pump would be the impeller coming loose from the shaft and not turning.
I would look at the heat exchanger insert. If they get scale covered, the heat will not transfer and will cause an overheat.
You don't mention how hot your engine is running, but the 125's do run at 190?, that is normal.
starting to suspect gauge. going to tear into heat exch. do u know if there is a kit containing all the o rings , bushings etc...that ill need to replace at reassembly?
Why don't you get one of those IR Temp guns and find out before you start randomly fixing things that may not be broken. I don't know if there is a kit or not.