yamaha overheating -low speed only

[deane]

1994 70 hp yamaha is overheating at low speed. Buzzer goes off before gauge indicates any problem. Engine is very hot (steaming). After shutdown the red alert shows on gauge. After cooling down works ok and can go at high speed without it overheating. Could it be oil injection system not supplying enough oil at low speed? Weep hole is shooting out lots of water at all speeds.

 

[Ray Neudecker]

Re: yamaha overheating -low speed only

This most likely will be a cooling system problem since the engine is hot. Obvious starting point is the water pump. The age would have me replace entire unit. Thermostats can be tested or replaced if in obvious need as a result of corrosion.