Yamaha MT-09 2021 - Adjusting the Valve Clearance; Checking the Spark Plugs

3-5
PERIODIC MAINTENANCE
EAS30620
CHECKING THE SPARK PLUGS
The following procedure applies to all of the
spark plugs.
1. Remove:
• Rider seat
Refer to “GENERAL CHASSIS (1)” on
page 4-1.
• Fuel tank center cover
Refer to “GENERAL CHASSIS (1)” on
page 4-1.
• Fuel tank
Refer to “FUEL TANK” on page 7-1.
• Air filter case
Refer to “GENERAL CHASSIS (2)” on
page 4-10.
2. Remove:
• Ignition coil
• Spark plug
NOTICE
ECA13320
Before removing the spark plugs, blow away
any dirt accumulated in the spark plug wells
with compressed air to prevent it from falling
into the cylinders.
3. Check:
• Spark plug type
Incorrect → Change.
4. Check:
• Electrode “1”
Damage/wear → Replace the spark plug.
• Insulator “2”
Abnormal color → Replace the spark plug.
Normal color is medium-to-light tan.
5. Clean:
• Spark plug
(with a spark plug cleaner or wire brush)
6. Measure:
• Spark plug gap “a”
(with a wire thickness gauge)
Out of specification → Regap.
7. Install:
• Spark plug
• Ignition coil
TIP
Before installing the spark plug, clean the spark
plug and gasket surface.
8. Install:
• Air filter case
Refer to “GENERAL CHASSIS (2)” on
page 4-10.
• Fuel tank
Refer to “FUEL TANK” on page 7-1.
• Fuel tank center cover
Refer to “GENERAL CHASSIS (1)” on
page 4-1.
• Rider seat
Refer to “GENERAL CHASSIS (1)” on
page 4-1.
EAS30622
ADJUSTING THE VALVE CLEARANCE
The following procedure applies to all of the
valves.
TIP
Valve clearance adjustment should be made on
a cold engine, at room temperature.
1. Remove:
• Rider seat
Refer to “GENERAL CHASSIS (1)” on
page 4-1.
• Fuel tank center cover
Refer to “GENERAL CHASSIS (1)” on
page 4-1.
• Fuel tank
Refer to “FUEL TANK” on page 7-1.
• Air filter case
Refer to “GENERAL CHASSIS (2)” on
page 4-10.
Manufacturer/model
NGK/LMAR9A-9
Spark plug gap
0.8–0.9 mm (0.031–0.035 in)
Spark plug
13 N·m (1.3 kgf·m, 9.6 lb·ft)
G088879
T
R
.
.