PERIODIC MAINTENANCE AND ADJUSTMENT
6-9
63. Remove the spark plug as shown,
with the spark plug wrench includ-
ed in the additional tool kit, which
was handed out separately at the
purchase of the vehicle. To check the spark plu
gs
1. Check that the porcelain insulator around the center electrode on
each spark plug is a medium-to-
light tan (the ideal color when the
vehicle is ridden normally).
2. Check that all spark plugs in- stalled in the engine have the
same color.
TIPIf any spark plug shows a distinctly dif-
ferent color, the engine could be oper-
ating improperly. Do not attempt to
diagnose such problems yourself. In-
stead, have a Yamaha dealer check
the vehicle.3. Check each spark plug for elec-trode erosion and excessive car-
bon or other deposits, and replace
it if necessary.
4. Measure the spark plug gap with a wire thickness gauge and, if nec-
essary, adjust the gap to specifi-
cation. To install a spark plu
g
1. Clean the surface of the spark plug gasket and its mating sur-
face, and then wipe off any grime
from the spark plug threads.
2. Install the spark plug with the spark plug wrench, and then tight-
en it to the specified torque.
1. Spark plug cap
1. Spark plug wrench
1
Specifie d spark plu g:
NGK/LMAR7A-9
1. Spark plug gapSpark plu g g ap:
0.8–0.9 mm (0.031–0.035 in)
Ti ghtenin g torque:
Spark plug: 13 Nm (1.3 m·kgf, 9.4 ft·lbf)
U2SSE1E0.book Page 9 Tuesday, October 28, 2014 11:08 AM
PERIODIC MAINTENANCE AND ADJUSTMENT
6-35
6
EAU42505
Troubleshootin g chartsStartin g pro blems or poor en gine 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.
U2SSE1E0.book Page 35 Tuesday, October 28, 2014 11:08 AM
