Yamaha F200B Service Manual page 123

Symptom 1: Unstable engine idle speed, poor acceleration, poor performance, or limited
engine speed.
Symptom 2
Spark plug does not
spark (some cylinders)
Fuel pressure is low
Fuel not supplied
(some cylinders)
Compression pressure
is low
—
Cause
Spark plug malfunction
Short, open, or loose
connection in ignition coil
circuit
Ignition coil malfunction
Engine ECM malfunction
—
Fuel leakage
Pressure regulator
malfunction
Clogged fuel filter element
High-pressure fuel pump
malfunction
Fuel injector malfunction
Short, open, or loose
connection in fuel injector
circuit
Clogged fuel injector filter
Engine ECM malfunction
—
Improper valve timing
Compression leakage
Improper pulser coil air gap
Outboard motor troubleshooting
Checking step
Check the ignition spark.
Check the spark plug.
Measure the ignition coil input voltage.
Check for continuity between the
ignition coil and the engine ECM.
Check for continuity between the
ignition coil and the main relay.
Check for continuity between the
ignition coil and ground.
Exchange the ignition coil with a
different one, and then check the
ignition spark.
Replace the engine ECM.
Measure fuel pressure.
Check for fuel leakage.
Check the pressure regulator.
Check the fuel filter element for dirt
and obstructions.
Measure the high-pressure fuel pump
resistance.
Check the fuel injector operation using
the YDIS.
Measure the fuel injector resistance.
Measure the fuel injector input voltage.
Check for continuity between the fuel
injector and the main relay.
Check for continuity between the fuel
injector and the engine ECM.
Replace the fuel injector.
Replace the engine ECM.
Measure the compression pressure.
Check the valve timing.
Check the timing belt.
Check the valve for bends and sticking.
Check the piston and piston rings for
damage.
Check the cylinder for scratches.
Measure the pulser coil air gap.
See
page
5-53
7-44
5-53
5-53
A-7
5-53
A-7
5-53
A-7
—
7-35
6-8 4
6-1
6-10
6-14
5-46
5-44
5-44
5-44
5-44
A-5
5-44
A-5
6-45
7-35
7-1
7-39
7-39
7-62
7-86
7-86
7-1
4-22