Yamaha F200B, Service Manual

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