2016 YAMAHA SR400 light

Periodic maintenance and adjustment
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EAU19605
Checking the spark plug
The spark plug is an important engine
component, which is easy to check.
Since heat and deposits will cause any
spark plug to slowly erode, the spark
plug should be removed and checked
in accordance with the periodic mainte-
nance and lubrication chart. In addition,
the condition of the spark plug can re-
veal the condition of the engine.
To remove the spark plug 1. Remove the spark plug cap.
2. Remove the spark plug as shown, with the spark plug wrench includ-
ed in the owner’s tool kit.
To check the spark plug 1. Check that the porcelain insulator around the center electrode of the spark plug is a medium-to-light tan
(the ideal color when the vehicle is
ridden normally).
TIP
If the 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.
2. Check the spark plug for electrode erosion and excessive carbon or
other deposits, and replace it if
necessary.
3. Measure the spark plug gap with a wire thickness gauge and, if nec-
essary, adjust the gap to specifica-
tion.
To install the spark plug 1. Clean the surface of the spark plug gasket and its mating surface, and
then wipe off any grime from the
spark plug threads.
2. Install the spark plug with the spark
1. Spark plug cap
1. Spark plug wrench
1
1
Specified spark plug: NGK/BPR6ES
1. Spark plug gap
Spark plug gap:0.7–0.8 mm (0.028–0.031 in)
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Periodic maintenance and adjustment
6-21
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decrease the brake pedal free play,
turn the adjusting nut in direction (b).
WARNING
EWA10681
After adjusting the drive chain
slack or removing and installing
the rear wheel, always check the
brake pedal free play.
If proper adjustment cannot be
obtained as described, have a
Yamaha dealer make this ad-
justment.
After adjusting the brake pedal
free play, check the operation of
the brake light.
EAU44821
Checking the shift pedal
The operation of the shift pedal should
be checked before each ride. If opera-
tion is not smooth, have a Yamaha
dealer check the vehicle.
1. Brake pedal free play adjusting nut
(b)
(a)
1
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Periodic maintenance and adjustment
6-22
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EAU22274
Brake light switches
The brake light, which is activated by
the brake pedal and brake lever, should
come on just before braking takes ef-
fect. If necessary, adjust the rear brake
light switch as follows, but the front
brake light switch should be adjusted
by a Yamaha dealer.
Turn the rear brake light switch adjust-
ing nut while holding the rear brake light
switch in place. To make the brake light
come on earlier, turn the adjusting nut
in direction (a). To make the brake light
come on later, turn the adjusting nut in
direction (b).
EAU22382
Checking the front brake pads
and rear brake shoes
The front brake pads and the rear brake
shoes must be checked for wear at the
intervals specified in the periodic main-
tenance and lubrication chart.
EAU22432Front brake pads
Each front brake pad is provided with
wear indicator grooves, which allow
you to check the brake pad wear with-
out having to disassemble the brake.
To check the brake pad wear, check
the wear indicator grooves. If a brake
pad has worn to the point that the wear
indicator grooves have almost disap-
peared, have a Yamaha dealer replace
the brake pads as a set.
1. Rear brake light switch adjusting nut
2. Rear brake light switch
2
1 (a)
(b)
1. Brake pad
2. Brake pad wear indicator groove
12
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Periodic maintenance and adjustment
6-26
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14 6. Take the motorcycle off the center-
stand, and then put the sidestand
down.
7. Tighten both drive chain puller locknuts to the specified torque,
and then tighten the axle nut and
brake torque rod nut to their speci-
fied torques.
8. Adjust the brake pedal free play. (See page 6-20.)
WARNING
EWA10661
After adjusting the brake pedal free
play, check the operation of the
brake light.
9. Make sure that the drive chain pull- ers are in the same position, the
drive chain slack is correct, and the
drive chain moves smoothly.
EAU23026
Cleaning and lubricating the
drive chain
The drive chain must be cleaned and
lubricated at the intervals specified in
the periodic maintenance and lubrica-
tion chart, otherwise it will quickly wear
out, especially when riding in dusty or
wet areas. Service the drive chain as
follows.
NOTICE
ECA10584
The drive chain must be lubricated
after washing the motorcycle, riding
in the rain or riding in wet areas.
1. Clean the drive chain with kero- sene and a small soft brush.
NOTICE: To prevent damaging
the O-rings, do not clean the
drive chain with steam cleaners,
high-pressure washers or inap-
propriate solvents.
[ECA11122]
2. Wipe the drive chain dry.
3. Thoroughly lubricate the drive chain with a special O-ring chain
lubricant. NOTICE: Do not use
engine oil or any other lubri-
cants for the drive chain, as they
may contain substances that
could damage the O-rings.
[ECA11112]
1. Axle nut
2. Drive chain puller locknut
3. Drive chain slack adjusting bolt
4. Alignment marks
Tightening torques: Drive chain puller locknut:16 Nm (1.6 m·kgf, 12 ft·lbf)
Axle nut: 129 Nm (12.9 m·kgf, 92 ft·lbf)
Brake torque rod nut:
19 Nm (1.9 m·kgf, 14 ft·lbf)
1
2
(a) (b)
3
4
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Periodic maintenance and adjustment
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14 If a fuse is blown, replace it as follows.
1. Turn the key to “OFF” and turn off the electrical circuit in question.
2. Remove the seat. (See page 3-13.)
3. Remove the blown fuse, and then install a new fuse of the specified
amperage. WARNING! Do not
use a fuse of a higher amperage
rating than recommended to
avoid causing extensive dam-
age to the electrical system and
possibly a fire.
[EWA15132]
4. Turn the key to “ON” and turn on the electrical circuit in question to
check if the device operates.
5. If a fuse immediately blows again, have a Yamaha dealer check the
electrical system.
1. Fuse box
1. Headlight fuse
2. Signaling system fuse
3. Ignition fuse
4. Backup fuse
5. Fuel injection system fuse
6. Parking lighting fuse
7. Spare fuse
1
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Specified fuses: Signaling system fuse:
15.0 A
Headlight fuse: 15.0 A
Ignition fuse: 10.0 A
Backup fuse:
7.5 A
Fuel injection system fuse: 7.5 A
Parking lighting fuse: 7.5 A
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Periodic maintenance and adjustment
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EAU23799
Replacing the headlight bulb
This model is equipped with a halogen
bulb headlight. If the headlight bulb
burns out, replace it as follows.
NOTICE
ECA10651
Take care not to damage the follow-
ing parts:
Headlight bulb
Do not touch the glass part of
the headlight bulb to keep it free
from oil, otherwise the transpar-
ency of the glass, the luminosity
of the bulb, and the bulb life will
be adversely affected. Thor-
oughly clean off any dirt and fin-
gerprints on the headlight bulb
using a cloth moistened with al-
cohol or thinner.
Headlight lens
Do not affix any type of tinted
film or stickers to the headlight
lens.
Do not use a headlight bulb of a
wattage higher than specified.
1. Remove the headlight unit by re- moving the screws. 2. Disconnect the headlight coupler,
and then remove the headlight
bulb cover.
3. Unhook the headlight bulb holder, and then remove the burnt-out
bulb.
1. Do not touch the glass part of the bulb.
1. Screw
1. Screw
1. Headlight coupler
2. Headlight bulb cover
1
1
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2
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Periodic maintenance and adjustment
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14 4. Place a new headlight bulb into po-
sition, and then secure it with the
bulb holder.
5. Install the bulb cover, and then connect the coupler.
6. Install the headlight unit by install- ing the screws.
7. Have a Yamaha dealer adjust the headlight beam if necessary.
EAU33417
Replacing the auxiliary light
bulb
If the auxiliary light bulb burns out, re-
place it as follows.1. Remove the headlight unit by re- moving the screws.
2. Remove the socket (together with the bulb) by pushing it in and turn-
ing it counterclockwise.
1. Headlight bulb holder
1
1. Screw
1. Screw
1. Auxiliary light bulb socket
1
1
1
2RD-28199-E1.book 36 ページ ２０１５年９月３日　木曜日　午後３時４２分

Periodic maintenance and adjustment
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3. Remove the burnt-out bulb by
pushing it in and turning it counter-
clockwise.
4. Insert a new bulb into the socket, push it in, and then turn it clock-
wise until it stops.
5. Install the socket (together with the bulb) by pushing it in and turning it
clockwise until it stops.
6. Install the headlight unit by install- ing the screws.
EAU24135
Replacing the tail/brake light
bulb
1. Remove the tail/brake light lens byremoving the screws.
2. Remove the burnt-out bulb by pushing it in and turning it counter-
clockwise.
3. Insert a new bulb into the socket, push it in, and then turn it clock-
wise until it stops.
4. Install the lens by installing the screws. NOTICE: Do not over-
tighten the screws, otherwise
the lens may break.
[ECA10682]
1. Auxiliary light bulb socket
2. Auxiliary light bulb
1
2
1. Screw
2. Tail/brake light lens
1. Tail/brake light bulb
1 2
1
2RD-28199-E1.book 37 ページ ２０１５年９月３日　木曜日　午後３時４２分