Yamaha F4B Service Manual page 56

TRBL
SHTG
Outboard motor troubleshooting
Troubleshooting procedure
1. Before troubleshooting the outboard motor, make sure that fresh fuel of the specified type has
been used.
2. Make sure that all electrical connections are secure and free from corrosion.
3. If the outboard motor is equipped with the charging system (optional for European market),
check that the battery is fully charged.
Troubleshooting the power unit
Troubleshooting consists of the following 3 items:
Symptom 1: Specific trouble conditions
Symptom 2: Trouble conditions of an area or individual part
Cause: Trouble causes of symptom 2
— : Not applicable
Symptom 1: Engine does not crank.
Symptom 2
Starter handle cannot be
pulled
Starter handle can be
pulled, but the engine
does not crank
Symptom 1: Engine will not start (engine cranks).
Symptom 2
Spark plug does not
spark
Fuel not supplied
4-1
Troubleshooting
Cause
Gear shift not in the N position Set the gear shift to the N position.
Start-in-gear protection cable
not adjusted properly
Manual starter malfunction
Decompressor malfunction
Stuck piston or crankshaft
Stuck drive shaft
Manual starter malfunction
Damaged flywheel magnet
Woodruff key
Cause
—
Spark plug malfunction
Spark plug cap malfunction
Engine shut-off switch malfunc-
tion
Fuel cock closed
Clogged fuel strainer
Fuel leakage
Fuel pump malfunction
Carburetor malfunction
Checking step
Adjust the start-in-gear protection cable.
Disassemble and check the manual
starter.
Check the camshaft.
Disassemble and check the power unit.
Disassemble and check the lower unit.
Disassemble and check the manual
starter.
Check the flywheel magnet Woodruff
key.
Checking step
Check the ignition spark.
Check the spark plug.
Check the spark plug cap.
Check the engine shut-off switch.
Set the fuel cock to the proper position.
Check the fuel strainer for clog or dirt.
Check the fuel line for fuel leakage.
Check the fuel pump for fuel leakage.
Check the diaphragm for tears.
Check the camshaft for wear.
Disassemble and clean the carburetor.
See
page
10-4
7-10
7-7
7-44
7-21
7-39
8-7
8-10
7-7
7-18
See
page
5-5
7-35
5-5
5-6
—
6-6
6-1
6-22
6-23
7-44
6-18