How to Tell if a Starter is Bad on your Marine Engine
When the starter on your marine engine refuses to crank, the engine’s starter may have gone bad.
First, you need to make sure the starter is really the source of the problem. Several other things: including a blown main fuse, not moving the throttle/shift lever into “neutral” before attempting to crank the motor, electrical connections that are not clean and tightly connected and wiring in poor condition can cause symptoms similar to those of a bad starter. So, go grab your multimeter and let’s do some testing! (NOTE: This is a good time to remove the lanyard from the emergency cut off switch to prevent the engine from accidentally starting)
Step 1: Turn the dial of a digital multimeter to the DC voltage setting. Place the red probe on the positive battery post and then the black probe on the negative battery post. If the multimeter indicates the battery is producing less than 11.3 volts, recharge or replace the battery before testing the starter.
Step 2: Set the multimeter to the DC voltage setting. Place the red lead of the multimeter on the positive terminal of the starter motor and then the black lead on the engine ground.
Step 3: Turn the ignition switch to the “Start” position. Read the voltage indicated on the multimeter.
Step 4: If the reading on the digital multimeter is greater than 9.5 volts, attempt to start the motor. If the motor fails to start when the reading on the digital multimeter is more than 9.5 volts, the starter requires replacement or rebuilding. A reading of less than 9.5 volts indicates a voltage loss between the battery and the starter; this should be corrected and then start the testing procedure again. (NOTE: This test is for a 12V operating system)
TIP: Before you crank the motor, shift it into “neutral.” The neutral lockout will prevent the motor from starting. Check the main fuse and inspect the wiring for broken or frayed wires.