1999 "EE" Evinrude 70HP 4-Stroke Service Manual, P/N 787023, Page 67Get this manual
I System Component
Faulty Thermostat Pressure Relief Valve Exhaust Temp Sensor Water Discharge Hose Damaged Water Pump Missing Flushing Plug Air in Cooling Water False Warning Blocked Water Intakes
Engine Overheats
CausesEffects
Overheat light, horn, and S.L.O.WOverheat light, horn, and S.L.O.WCode
14 14 or 15
Actions
Inspect thermostat for blockage or damageTest in hot watershould open at 122F (50C) Check for damaged or plugged relief valve or relief valve assembled backwardsNormal system pressure is about 5.5 PSI (40 kPa) Check for both items listed aboveon late models only from powerhead adapter and Remove fitting run engine briefly while watching for considerable water flow Run engine for short time with flushing plug removed from midsectionconsiderable water discharge should be observed Replace plug Lower engine on transom or block sub-water intake Verify overheat using pyrometerrepair as necessary Clean as necessary