I have an OMC 1982 inboard changed w.pump and thermostat still runs hot what else could it be?

Question

I have an OMC 1982 inboard changed w.pump and thermostat still runs hot what else could it be?

Answer 1

check for clogged hoses/ screens

Answer 2

In a closed system> Heat exchanger> If not than the elbow or manifolds>

Answer 3

Did you change the water pump on the motor ? if so you should change the impeller on the lower unit that is how the water gets to the engine also check screen on lower unit might be clogged.

Answer 4

the heat risers

Answer 5

9 times out of 10 it's going to be corroded exhaust riser elbows on an OMC. It's a pretty bad design.

Answer 6

I would say that it is your heat exchanger.  It will build up scale and rust inside and not allow the water to pass through properly to provide cooling.   You may be able to have it cleaned but if it is the original you will be better off to purchase a new one.  

Good Luck and Boat Safe ! !

Answer 7

Take the thermostat out and run the engine for at least a couple hours, ( don't go above 200 but it should clear up circulation problems.  There should be 2 water pumps, you said you changed one?  Look at belts for the engine pump.  Good luck!

Answer 8

how abotu radiator...the radiator itself, all the hoses running to it and from it.  That old the hoses may be split or cracked somewhere.

Answer 9

Also check the exhaust elbow(s)