spark plugs replace YAMAHA XSR 900 2018 Owners Manual

Periodic maintenance and adjustment
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EAU71031
TIP
The annual checks must be performed every year, except if a distance-based maintenance is performed in-
stead.

From 50000 km (30000 mi), repeat the maintenance intervals starting from 10000 km (6000 mi).

Items marked with an asterisk should be performed by a Yamaha dealer as they require special tools, data and technicalskills.
EAU71051
Periodic maintenance chart for the emission control systemNO. ITEM CHECK OR MAINTENANCE JOB ODOMETER READING
ANNUAL
CHECK
1000 km
(600 mi) 10000 km
(6000 mi) 20000 km
(12000 mi) 30000 km
(18000 mi) 40000 km
(24000 mi)
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 synchronization. 
5 * Exhaust system Check for leakage.
Tighten if necessary.
Replace gaskets if necessary. 
6* Evaporative
emission control
system Check control system for damage.
Replace if necessary.

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Periodic maintenance and adjustment
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EAU19653
Checking the spark plugsThe spark plugs are important engine
components, which should be checked
periodically, preferably by a Yamaha
dealer. Since heat and deposits will
cause any spark plug to slowly erode,
they should be removed and checked
in accordance with the periodic mainte-
nance and lubrication chart. In addition,
the condition of the spark plugs can re-
veal the condition of the engine.
The porcelain insulator around the cen-
ter 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 en-
gine should have the same color. If any
spark plug shows a distinctly different
color, the engine could be operating im-
properly. Do not attempt to diagnose
such problems yourself. Instead, have
a Yamaha dealer check the vehicle.
If a spark plug shows signs of electrode
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.
TIPIf a torque wrench is not available wheninstalling 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 speci-
fied torque as soon as possible.NOTICE
ECA10841
Do not use any tools to remove or in-
stall the spark plug cap, otherwise
the ignition coil coupler may get
damaged. The spark plug cap may
be difficult to remove because the
rubber seal on the end of the cap fits
tightly. To remove the spark plug
cap, simply twist it back and forth
while pulling it out; to install it, twistit back and forth while pushing it in.
Specified spark plug:
NGK/CPR9EA9
1. Spark plug gapSpark 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)
UB90E2.book 9 ページ ２０１８年６月５日　火曜日　午後５時４０分

Periodic maintenance and adjustment6-37
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Troubleshooting chartsStarting problems or poor engine performance
Check the fuel level in
the fuel tank.1. Fuel
There is enough fuel.
There is no fuel.
Check the battery.
Supply fuel.
The engine does not start.
Check the battery.
Remove the spark plugs
and check the electrodes.3. Ignition
Wipe off with a dry cloth and correct the
spark plug gaps, or replace the spark plugs.
Have a Yamaha dealer check the vehicle.
Operate the electric starter.4. Compression
There is compression.
There is no compression.
The engine does not start.
Have a Yamaha dealer check the vehicle.Have a Yamaha dealer check the vehicle.
The engine does not start.
Check the compression.
Operate the electric starter.2. Battery
The engine turns over
quickly.
The engine turns over
slowly.
The engine does not start.
Check the ignition.
The battery is good.Check the battery lead connections,
and have a Yamaha dealer charge
the battery if necessary.
DryWet
Operate the electric starter.
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