30hp evinrude, alarm sounding, only running at idle speed. over heating?

[marstranded]

I just bought a used boat with a 30hp evinrude. When I took it out for a test it ran great for about five minutes and then an alarm sounded on the control unit. It would only run at idle speed after that. It was peeing water through the tube, but I suspect that it might of been overheating. Need help troubleshooting. Thanks

 

[joereeves]

The overheat alarm... a constant beeping of the warning horn sounds before any damage is done. If you ignored it and continued running to a point where it really overheated and/or seized up, well, that's not good!

Check all powerhead bolts, screws, nuts... heat causes them to come loose. Figure on a new head gasket which will require torquing down to factory specifications in the following sequence whereas each number represents a bolt

9...10
5....6
1....2
4....3
8....7

Drop the lower unit, dismantle the water pump and repair/replace as needed.