Yamaha F50F Service Manual page 293

Ignition system
Check the condition of the spark
plugs.
Good condition?
Yes
Check the ignition spark using
the ignition tester.
Good spark?
No
Check the resistance of each
ignition coil.
Good condition?
Yes
Check the resistance of each
spark plug wire and check the
spark plug caps for salt buildup.
Good condition?
Yes
Check the ECM output peak
voltage.
6C13G11
No
Clean, adjust, or replace the
spark plugs.
WARNING
• Do not touch any of the connections of the ignition 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
Replace the ignition coils.
No
Repair or replace the spark plug
wire.
Power unit
1
2
3
4
5
6
7
8
9
9-20