0306530 EVINRUDE SCREW,Crankcase to cylinder

Low or No Battery Voltage
Check battery voltage. If battery voltage is less than 8 volts for a 12 volt system, or 16 volts for a 24 volt system, put a charge to the battery. If battery will not hold a charge, load test the battery as shown in the Electrical System of the Testing and Adjusting section of this Service Manual.Bad Switch, Bad Wiring or Connection in Switch Circuit
With ignition switch in START position, check voltage at switch connection on starter solenoid. If there is no voltage, or if the voltage is low at this connection, check wiring, connections, ignition switch, and magnetic switch (if used).Bad Cable or Connection; Battery to Starter
With ignition switch in the START position, check voltage at connection of battery cable to starter. If there is no voltage, or if the voltage is low at this connection and there is good voltage at the battery, check for bad cable or connection between the battery and the starter.Bad Starter Solenoid
Remove and repair a solenoid which does not work when voltage is correct at both the battery and ignition switch connections.Bad Starter Motor
If the solenoid works and the starter motor does not turn the crankshaft, the starter motor is bad. Before removing the starter motor, turn the crankshaft by hand to be sure a mechanical failure inside the engine, transmission, or power take-off is not preventing the crankshaft from turning. If crankshaft turns freely by hand, engage the starter motor again. If the starter motor still will not work, remove the starter motor and repair it, or install a new starter motor.Transmission or Power Take-off (if so equipped) Problem Prevents Crankshaft From Turning
If crankshaft can not be turned by hand, disconnect the transmission and power take-off. If crankshaft will now turn, find the cause of the problem in the transmission or power take-off and make necessary corrections.Inside Problem Prevents Engine Crankshaft From Turning
If the crankshaft can not be turned after disconnecting the transmission and power take-off, remove the fuel nozzles and check for fluid in the cylinders while turning the crankshaft. If fluid in the cylinders is not the problem, the engine must be disassembled to check for other inside problems. Some of these inside problems are bearing seizure, piston seizure, and valves making contact with pistons.Engine Crankshaft Turns Too Slowly
Possible Causes/CorrectionsLow Battery Voltage
Check battery voltage. If battery voltage is less than 8 volts for a 12 volt system, or 16 volts for a 24 volt system, put a charge to the battery. If the battery will not hold a charge, load test the battery as shown in the Electrical System of the Testing and Adjusting section of this Service Manual.Bad Cable or Connection; Battery to Starter
With switch in START position, check voltage at battery cable connection to starter. If voltage is low at this connection and there is good voltage at the battery, check for bad cable or connection between the battery and the starter.Oil Too Thick for Free Crankshaft Rotation
Use the correct SAE grade oils for the temperatures that the engine is operated in. Make reference to the Operator's Guide. At temperatures below -23°C (-10°F) it may be necessary to warm the oil for free crankshaft rotation.Bad Starter Motor
Remove and test. Make repairs as necessary or install a new starter motor.Extra Outside Loads
Damage to the power take-off equipment (if so equipped) and, or transmission can put extra load on the engine. This prevents free rotation of the crankshaft. To check, disconnect the transmission and power take-off, and start the engine.Mechanical Problem Inside Engine
Take the engine apart and check all components for damage.