Troubleshooting - Yamaha UMAX Service Manual

TROUBLESHOOTING

The ignition system fails to operate (no spark or intermittent spark).
TIP
• Before troubleshooting, remove the following part(s):
1. Under-seat panel
2. Service lid
3. Instrument panel assembly
1. Check the fuses.
(Main and Main switch)
Refer to "CHECKING THE FUSES"
on page 8-50.
OK ↓
2. Check the battery.
Refer to "CHECKING AND
CHARGING THE BATTERY" on
page 8-51.
OK ↓
3. Check the spark plug.
Refer to "CHECKING THE SPARK
PLUG (YUM1A/YUM2A)" on page
3-10.
OK ↓
4. Check the ignition spark gap.
Refer to "CHECKING THE IGNI-
TION SPARK GAP" on page 8-54.
NG ↓
5. Check the spark plug cap.
Refer to "CHECKING THE SPARK
PLUG CAP" on page 8-54.
OK ↓
6. Check the ignition coil.
Refer to "CHECKING THE IGNI-
TION COIL" on page 8-54.
OK ↓
7. Check the crankshaft position sen-
sor.
Refer to "CHECKING THE CRANK-
SHAFT POSITION SENSOR" on
page 8-55.
OK ↓
IGNITION SYSTEM (YUM1A/YUM2A)
NG →
Replace the fuse(s).
NG →
• Clean the battery terminals.
• Recharge or replace the battery.
NG →
Re-gap or replace the spark plug.
OK →
Ignition system is OK.
NG →
Replace the spark plug cap.
NG →
Replace the ignition coil.
NG →
Replace the crankshaft position sensor.
8-3