2007 300DF overheating

[BrownieNpadre]

Motor was running fine for about 40 minutes then started overheating. I have check thermostat and the heat sensor. It is peeing great and water exiting is not hot. Could it still be the water pump? Any other ideas?

[Hoosmatroos]

If the pee is strong then it's not likely that the impeller is broken. It's possible that there is a partial blockage in the cooling system.
When you are running, is that WOT or just cruising? Did you check the actual temp of the motor with an infrared temp gun? Then you know if you have to look for a sensor or not.

[BrownieNpadre]

I did not use a temp, gauge, however I swapped sensor from one ot the other motors. It does not over heat at low rpm but once you start getting to around 3000 heat goes up and will get to 200 pretty fast and once you pull back on the throttles it will return to normal fairly quickly.

[Hoosmatroos]

When was the last time that you changed the impeller? You could start with that to be sure, also check the housing for wear

[BrownieNpadre]

Trying to find out just bought the boat. Ids there anyway to back wash the system to try dislodge a blockage?

[Hoosmatroos]

Yes, you can try. Remove the lower unit to do so. Change the impeller also at that point. If the lower end is off then changing the impeller is a piece of cake.

[redlowrey]

Motor was running fine for about 40 minutes then started overheating. I have check thermostat and the heat sensor. It is peeing great and water exiting is not hot. Could it still be the water pump? Any other ideas?

''''''I am assuming you changed both thermostats,