Yamaha F150A Service Manual page 301

Ignition system
Check the condition of the spark
plugs.
Good condition?
Yes
Check the ignition spark using
the spark gap tester.
Good spark?
No
Check the ignition coil resis-
tance.
Good condition?
Yes
Check the spark plug wire resis-
tance and check the spark plug
caps for salt buildup.
Good condition?
Yes
Check the ECM output peak
voltage.
63P3F11
No
Clean, adjust, or replace the
spark plugs.
WARNING
• Do not touch any of the connections of the spark gap tester leads.
• Do not let sparks leak out of the removed spark plug caps.
• Keep flammable gas and liquids away, since this test can produce
sparks.
Yes
Check the fuel system.
No
Repair or replace the defective
parts.
No
Repair or replace the spark plug
wires.
Power unit
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