Troubleshooting - Yamaha CS50 Service Manual

EAS00736

TROUBLESHOOTING

The ignition system fails to operate
(no spark or intermittent spark).
Check:
1. Spark plug
2. Ignition spark gap
3. Spark plug cap resistance
4. Ignition coil resistance
5. Main switch
6. Pickup coil resistance
7. Main fuse
8. Battery
9. Wiring connections (of the entire ignition
system)
NOTE:
• Before troubleshooting, remove the follo-
wing part(s):
1.Front upper cover
2.Footrest board
• Troubleshoot with the following special
tool(s).
Ignition checker
90890-06754
Pocket tester
90890-03112
IGNITION SYSTEM
EAS00740
1. Spark plug
• Check the condition of the spark plug.
• Check the spark plug type.
• Measure the spark plug gap.
Refer to "CHECKING THE SPARK PLUG" in
chapter 3.
Standard spark plug
BR8HS (NGK)
Spark plug gap
0.6 ~ 0.7 mm
• Is the spark plug in good condition, is it of
the correct type, and is its gap within spe-
cification?
YES
EAS00742
2. Ignition spark gap
• Disconnect the spark plug cap from the
spark plug.
• Connect the ignition checker
Spark plug cap
• Set the main switch to "ON".
• Measure the ignition spark gap
• Crank the engine by pushing the starter
switch and gradually increase the spark
gap until a misfire occurs.
Minimum ignition spark gap
6,0 mm
• Is there a spark and is the spark gap within
specification?
YES
8-9
ELEC
NO
Re-gap or replace
the spark plug.
as shown.
.
NO
The ignition system
is OK.