FAULT TRACING Engine does not start Engine stops Engine not reaching correct temp at full rpm Engine runs roughly or vibrates Engine becomes Fault abnormaly abnormally hot Stop control not fully pushed back . Main switch : not switched on . Flat battery . Broken electric wires . Main fuse blown . " Empty fuel tank, closed fuel cock or clogged fuel filter . " " " Water or impurities in the fuel . Faulty injectors or air in the fuel system . " Boat abnormally loaded, clogged intake air filter or marine growth on the boat bottom . Engine not properly aligned . Propeler damaged . " Clogged cooling water intake or water jackets in the exhaust manifold . Faulty impeller in sea-water pump .
Faulty thermostat . Cloged cooling water pipe in the cylinder head .