Yamaha YZ 2018 Series, Owner'S Service Manual

Page: 302 / 402

IGNITION SYSTEM
8-3
EASB29B325
TROUBLESHOOTING
The ignition system fails to operate (no spark or intermittent spark).
TIP
Before troubleshooting, remove the following part (s):
1. Seat
2. Side cover (left/right)
3. Air scoop (left/right)
4. Fuel tank
5. Air filter case cover
1. Check the fuse.
Refer to “CHECKING THE FUSES”
on page 8-60.
NG

Replace the fuse(s).
OK

2. Check the battery.
Refer to “CHECKING AND
CHARGING THE BATTERY” on
page 8-61.
NG

• Clean the battery terminals.
• Recharge or replace the battery.
OK

3. Check the spark plug.
Refer to “CHECKING THE SPARK
PLUG” on page 3-37.
NG

Re-gap or replace the spark plug.
OK

4. Check the ignition spark gap.
Refer to “CHECKING THE IGNI-
TION SPARK GAP” on page 8-66.
OK

The ignition system is normal.
NG

5. Check the ignition coil.
Refer to “CHECKING THE IGNI-
TION COIL” on page 8-66.
NG

Replace the ignition coil.
OK

6. Check the crankshaft position sen-
sor.
Refer to “CHECKING THE CRANK-
SHAFT POSITION SENSOR” on
page 8-67.
NG

Replace the stator assembly.
OK

7. Check the engine stop switch.
Refer to “CHECKING THE
SWITCHES” on page 8-57.
NG

Replace the engine stop switch.
OK
