955513 Volvo.Penta Hexagon screw

Troubleshooting Problems
The Engine Crankshaft Will Not Turn When The Start Switch Is On
Probable Cause
Low output from the batteryCheck the condition of the battery. Charge the battery or replace the battery, as required.
Faulty wires or switchesRepair the wires or the switches or replace the wires or the switches, as required.
Faulty starting motor solenoidInstall a new starting motor solenoid.
Faulty starting motorInstall a new starting motor.
An internal problem prevents the turning of the engine crankshaft.If the crankshaft cannot be turned after disconnecting the driven equipment, inspect the cylinders for fluid while the crankshaft is being turned. If fluid in the cylinders is not the problem, the engine must be disassembled. After disassembling the engine, inspect the engine for other internal problems. Possible internal problems include the following conditions:
Bearing seizure
Piston seizure
Valve and piston contactThe Engine Will Not Start
Probable Cause
Slow cranking speedCheck the condition of the battery. Charge the battery or replace the battery, as required. Inspect all cables and connections. All connections should be cleaned and tightened. Replace all faulty parts.
No fuel in the housing for the fuel injection pumpsUse the priming pump in order to fill the housing for the fuel injection pumps with fuel. Remove the air with the purge valve.
Dirty fuel filterInstall a new fuel filter.
Broken fuel lines or dirty fuel linesNew fuel lines should be cleaned or installed, as required.
No fuel to the cylindersPut fuel in the fuel tank. Prime the fuel system.
Low