spark plugs replace YAMAHA MT-03 2020 Owners Manual

Periodic maintenance and adjustment
6-3
6
EAU71033
Periodic maintenance charts
TIP
Items marked with an asterisk should be performed by your Yamaha dealer
because these items require special tools, data, and technical skills.
From 50000 km (30000 mi), repeat the maintenance intervals starting from
10000 km (6000 mi).
The annual checks must be performed every year, except if a distance-
based maintenance is performed instead.
EAU71071
Periodic maintenance chart for the emission control system
NO. ITEM
1*Fuel line• Check fuel hoses for cracks or
damage.
• Replace if necessary.√√√√√
2*Spark plugs• Check condition.
• Adjust gap and clean.√√
• Replace.√√
3*Valve clearance• Check and adjust. Every 40000 km (24000 mi)
4*Fuel injection• Check engine idle speed.√√√√√√
• Check and adjust synchroniza-
tion.√√√√√
5*Exhaust system• Check for leakage.
• Tighten if necessary.
• Replace gaskets if necessary.√√√√√
6*Evaporative emis-
sion control sys-
tem• Check control system for dam-
age.
• Replace if necessary.√√
7*Air induction sys-
tem• Check the air cut-off valve, reed
valve, and hose for damage.
• Replace any damaged parts if
necessary.√√√√√X 1000 km CHECK OR
MAINTENANCE JOB
X 1000 mi
ODOMETER
READINGS
ANNUAL CHECK
110203040
0.66121824
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Periodic maintenance and adjustment
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6
EAU19643
Checking the spark plugs
The spark plugs are important engine
components, which should be
checked periodically, preferably by a
Yamaha dealer. Since heat and depos-
its will cause any spark plug to slowly
erode, they should be removed and
checked in accordance with the peri-
odic maintenance and lubrication
chart. In addition, the condition of the
spark plugs can reveal the condition of
the engine.
The porcelain insulator around the
center electrode of each spark plug
should be a medium-to-light tan (the
ideal color when the vehicle is ridden
normally), and all spark plugs installed
in the engine should have the same
color. If any spark plug shows a dis-
tinctly different color, the engine could
be operating improperly. Do not at-
tempt to diagnose such problems
yourself. Instead, have a Yamaha deal-
er check the vehicle.
If a spark plug shows signs of elec-
trode erosion and excessive carbon or
other deposits, it should be replaced.
Before installing a spark plug, the
spark plug gap should be measured
with a wire thickness gauge and, if
necessary, adjusted to specification.Clean the surface of the spark plug
gasket and its mating surface, and
then wipe off any grime from the spark
plug threads.
TIP
If a torque wrench is not available
when installing a spark plug, a good
estimate of the correct torque is 1/4…
1/2 turn past finger tight. However, the
spark plug should be tightened to the
specified torque as soon as possible.
Specified spark plug:
NGK/LMAR8A-9
1. Spark plug gap
Spark plug gap:
0.8–0.9 mm (0.031–0.035 in)
Tightening torque:
Spark plug:
13 N·m (1.3 kgf·m, 9.6 lb·ft)
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