engine YAMAHA SR400 2016 Owner's Guide

Periodic maintenance and adjustment
6-12
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8
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14 12. Add the specified amount of the
recommended engine oil, and then
install and tighten the oil filler cap.
TIP
Be sure to wipe off spilled oil on any
parts after the engine and exhaust sys-
tem have cooled down.
NOTICE
ECA11621
In order to prevent clutch slip-
page (since the engine oil also
lubricates the clutch), do not
mix any chemical additives. Do
not use oils with a diesel speci-
fication of “CD” or oils of a high-
er quality than specified. In
addition, do not use oils labeled
“ENERGY CONSERVING II” or
higher.
Make sure that no foreign mate-
rial enters the crankcase.
13. Start the engine, and then let it idle for several minutes while checking
it for oil leakage. If oil is leaking, im-
mediately turn the engine off and
check for the cause.
14. Turn the engine off, and then check the oil level and correct it if necessary.
NOTICE
ECA11232
After changing the engine oil, make
sure to check the oil pressure as de-
scribed below.
Loosen the bleed bolt.
Start the engine and keep it
idling until oil flows out. If no oil
comes out after one minute,
turn the engine off immediately
so it will not seize. If this occurs,
have a Yamaha dealer repair the
vehicle.
After checking the oil pressure,
tighten the bleed bolt to the
specified torque.
Tightening torques:
Engine oil drain bolt (crankcase):
30 Nm (3.0 m·kgf, 22 ft·lbf)
Engine oil drain bolt (oil tank): 16 Nm (1.6 m·kgf, 12 ft·lbf)
Recommended engine oil: See page 8-1.
Oil quantity:
Oil change:2.00 L (2.11 US qt, 1.76 Imp.qt)
With oil filter removal:
2.10 L (2.22 US qt, 1.85 Imp.qt)
1. Bleed bolt
Tightening torque:Bleed bolt:
18 Nm (1.8 m·kgf, 13 ft·lbf)
1
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Periodic maintenance and adjustment
6-13
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7
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14
EAU52031
Replacing the air filter element
The air filter element should be re-
placed at the intervals specified in the
periodic maintenance and lubrication
chart. Replace the air filter element
more frequently if you are riding in un-
usually wet or dusty areas.
To replace the air filter element 1. Remove panel A. (See page 6-7.)
2. Remove the air filter case cover by removing the screws.
3. Pull the air filter element out.
4. Insert a new air filter element into the air filter case. NOTICE: Make
sure that the air filter element is
properly seated in the air filter
case. The engine should never
be operated without the air filter element installed, otherwise the
piston(s) and/or cylinder(s) may
become excessively worn.[ECA10482]
5. Install the air filter case cover by in-
stalling the screws.
6. Install the panel.
1. Screw
2. Air filter case cover
1. Air filter element
1
2
1
1
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Periodic maintenance and adjustment
6-14
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2
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8
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14
EAU44735
Checking the engine idling
speed
Check the engine idling speed and, if
necessary, have it corrected by a
Yamaha dealer.
EAU21386
Checking the throttle grip free
play
Measure the throttle grip free play as
shown.
Periodically check the throttle grip free
play and, if necessary, have a Yamaha
dealer adjust it.
Engine idling speed: 1200–1400 r/min
1. Throttle grip free play
Throttle grip free play:3.0–5.0 mm (0.12–0.20 in)
1
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Periodic maintenance and adjustment
6-15
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EAU21402
Valve clearance
The valve clearance changes with use,
resulting in improper air-fuel mixture
and/or engine noise. To prevent this
from occurring, the valve clearance
must be adjusted by a Yamaha dealer
at the intervals specified in the periodic
maintenance and lubrication chart.
EAU70280
Tires
Tires are the only contact between the
vehicle and the road. Safety in all con-
ditions of riding depends on a relatively
small area of road contact. Therefore, it
is essential to maintain the tires in good
condition at all times and replace them
at the appropriate time with the speci-
fied tires.
Tire air pressure
The tire air pressure should be checked
and, if necessary, adjusted before each
ride.
WARNING
EWA10504
Operation of this vehicle with im-
proper tire pressure may cause se-
vere injury or death from loss of
control.
The tire air pressure must be
checked and adjusted on cold
tires (i.e., when the temperature
of the tires equals the ambient
temperature).
The tire air pressure must be ad-
justed in accordance with the
riding speed and with the total
weight of rider, passenger, car-
go, and accessories approved
for this model.
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Periodic maintenance and adjustment
6-26
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7
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13
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
6-43
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EAU67930
Troubleshooting chart
1. FuelThere is enough fuel.
There is no fuel.Supply fuel.
Check the battery.
The turn signal
flashes brightly.
The turn signal does
not flash or is weak.
The engine does not
start.
Check the battery.
Wipe off with a dry
cloth and correct the
spark plug gap, or
replace the spark
plug.
Check the battery
lead connections,
and have a Yamaha
dealer charge the
battery if necessary.
Operate the
kickstarter.
If the engine does
not start, check the
ignition.
2. BatteryThe battery is good.
3. IgnitionWet
Dry
There is compression.
There is no
compression.
Operate the
kickstarter.
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.Have a Yamaha
dealer check the
vehicle.
Remove the spark
plug and check
the electrodes.
With the key in the on
position, operate the
turn signal switch.
Operate the
kickstarter.
Check the fuel level
in the fuel tank.
4. Compression
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7-1
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Motorcycle care and storage
EAU37834
Matte color caution
NOTICE
ECA15193
Some models are equipped with
matte colored finished parts. Be
sure to consult a Yamaha dealer for
advice on what products to use be-
fore cleaning the vehicle. Using a
brush, harsh chemical products or
cleaning compounds when cleaning
these parts will scratch or damage
their surface. Wax also should not
be applied to any matte colored fin-
ished parts.
EAU26005
Care
While the open design of a motorcycle
reveals the attractiveness of the tech-
nology, it also makes it more vulnera-
ble. Rust and corrosion can develop
even if high-quality components are
used. A rusty exhaust pipe may go un-
noticed on a car, however, it detracts
from the overall appearance of a motor-
cycle. Frequent and proper care does
not only comply with the terms of the
warranty, but it will also keep your mo-
torcycle looking good, extend its life
and optimize its performance.
Before cleaning 1. Cover the muffler outlet with a plastic bag after the engine has
cooled down.
2. Make sure that all caps and covers as well as all electrical couplers
and connectors, including the
spark plug cap, are tightly in-
stalled.
3. Remove extremely stubborn dirt, like oil burnt onto the crankcase,
with a degreasing agent and a
brush, but never apply such prod-
ucts onto seals, gaskets, sprock-
ets, the drive chain and wheel
axles. Always rinse the dirt and de-
greaser off with water.
Cleaning
NOTICE
ECA10773
Avoid using strong acidic wheel
cleaners, especially on spoked
wheels. If such products are
used on hard-to-remove dirt, do
not leave the cleaner on the af-
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Motorcycle care and storage
7-2
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fected area any longer than in-
structed. Also, thoroughly rinse
the area off with water, immedi-
ately dry it, and then apply a cor-
rosion protection spray.
Improper cleaning can damage
plastic parts (such as cowlings,
panels, windshields, headlight
lenses, meter lenses, etc.) and
the mufflers. Use only a soft,
clean cloth or sponge with wa-
ter to clean plastic. However, if
the plastic parts cannot be thor-
oughly cleaned with water, di-
luted mild detergent with water
may be used. Be sure to rinse
off any detergent residue using
plenty of water, as it is harmful
to plastic parts.
Do not use any harsh chemical
products on plastic parts. Be
sure to avoid using cloths or
sponges which have been in
contact with strong or abrasive
cleaning products, solvent or
thinner, fuel (gasoline), rust re-
movers or inhibitors, brake flu-
id, antifreeze or electrolyte.
Do not use high-pressure wash-
ers or steam-jet cleaners since
they cause water seepage and
deterioration in the following ar-
eas: seals (of wheel and swing-
arm bearings, fork and brakes),
electric components (couplers,
connectors, instruments,
switches and lights), breather
hoses and vents.
For motorcycles equipped with
a windshield: Do not use strong
cleaners or hard sponges as
they will cause dulling or scratching. Some cleaning com-
pounds for plastic may leave
scratches on the windshield.
Test the product on a small hid-
den part of the windshield to
make sure that it does not leave
any marks. If the windshield is
scratched, use a quality plastic
polishing compound after
washing.
After normal use
Remove dirt with warm water, a mild
detergent, and a soft, clean sponge,
and then rinse thoroughly with clean
water. Use a toothbrush or bottlebrush
for hard-to-reach areas. Stubborn dirt
and insects will come off more easily if
the area is covered with a wet cloth for
a few minutes before cleaning.
After riding in the rain, near the sea or
on salt-sprayed roads
Since sea salt or salt sprayed on roads
during winter are extremely corrosive in
combination with water, carry out the
following steps after each ride in the
rain, near the sea or on salt-sprayed
roads.
TIP
Salt sprayed on roads in the winter may
remain well into spring. 1. Clean the motorcycle with cold wa- ter and a mild detergent, after the
engine has cooled down.
NOTICE: Do not use warm water
since it increases the corrosive
action of the salt.
[ECA10792]
2. Apply a corrosion protection sprayon all metal, including chrome- and
nickel-plated, surfaces to prevent
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Motorcycle care and storage
7-4
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14
EAU43204
Storage
Short-term
Always store your motorcycle in a cool,
dry place and, if necessary, protect it
against dust with a porous cover. Be
sure the engine and the exhaust sys-
tem are cool before covering the motor-
cycle.
NOTICE
ECA10811
Storing the motorcycle in a
poorly ventilated room or cover-
ing it with a tarp, while it is still
wet, will allow water and humid-
ity to seep in and cause rust.
To prevent corrosion, avoid
damp cellars, stables (because
of the presence of ammonia)
and areas where strong chemi-
cals are stored.
Long-term
Before storing your motorcycle for sev-
eral months: 1. Follow all the instructions in the “Care” section of this chapter.
2. Fill up the fuel tank and add fuel stabilizer (if available) to prevent
the fuel tank from rusting and the
fuel from deteriorating.
3. Perform the following steps to pro- tect the cylinder, piston rings, etc.
from corrosion.
a. Remove the spark plug cap and spark plug.
b. Pour a teaspoonful of engine oil into the spark plug bore.
c. Install the spark plug cap onto the spark plug, and then place
the spark plug on the cylinder head so that the electrodes are
grounded. (This will limit spark-
ing during the next step.)
d. Turn the engine over several
times with the starter. (This will
coat the cylinder wall with oil.)
WARNING! To prevent dam-
age or injury from sparking,
make sure to ground the
spark plug electrodes while
turning the engine
over.
[EWA10952]
e. Remove the spark plug capfrom the spark plug, and then
install the spark plug and the
spark plug cap.
4. Lubricate all control cables and the pivoting points of all levers and
pedals as well as of the sides-
tand/centerstand.
5. Check and, if necessary, correct the tire air pressure, and then lift
the motorcycle so that both of its
wheels are off the ground. Alterna-
tively, turn the wheels a little every
month in order to prevent the tires
from becoming degraded in one
spot.
6. Cover the muffler outlet with a plastic bag to prevent moisture
from entering it.
7. Remove the battery and fully charge it. Store it in a cool, dry
place and charge it once a month.
Do not store the battery in an ex-
cessively cold or warm place [less
than 0  C (30 F) or more than 30
 C (90 F)]. For more information
on storing the battery, see page
6-31.
TIP
Make any necessary repairs before
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8-1
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9
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Specifications
EAU69993Dimensions:
Overall length: 2085 mm (82.1 in)
Overall width: 750 mm (29.5 in)
Overall height:
1095 mm (43.1 in)
Seat height: 785 mm (30.9 in)
Wheelbase: 1410 mm (55.5 in)
Ground clearance:
130 mm (5.12 in)
Minimum turning radius: 2.4 m (7.87 ft)
Weight:
Curb weight:
174 kg (384 lb)
Engine:
Combustion cycle:4-stroke
Cooling system:
Air cooled
Valve train: SOHC
Number of cylinders: Single cylinder
Displacement:
399 cm
3
Bore  stroke:
87.0  67.2 mm (3.43  2.65 in)
Compression ratio: 8.5 : 1
Starting system:
Kickstarter
Lubrication system: Dry sump
Engine oil:
Recommended brand:
YAMALUBE
SAE viscosity grades: 10W-40
Recommended engine oil grade:
API service SG type or higher, JASO stan-
dard MA
Engine oil quantity:
Oil change:2.00 L (2.11 US qt, 1.76 Imp.qt)
With oil filter removal:
2.10 L (2.22 US qt, 1.85 Imp.qt)
Air filter:
Air filter element:Oil-coated paper element
Fuel:
Recommended fuel:
Regular unleaded gasoline (Gasohol [E10]
acceptable)
Fuel tank capacity:
12 L (3.2 US gal, 2.6 Imp.gal)
Fuel reserve amount: 2.2 L (0.58 US gal, 0.48 Imp.gal)
Fuel injection:
Throttle body:
ID mark: 2RD1 00
Spark plug(s):
Manufacturer/model:NGK/BPR6ES
Spark plug gap: 0.7–0.8 mm (0.028–0.031 in)
Clutch:
Clutch type:Wet, multiple-disc
Drivetrain:
Primary reduction ratio:
2.567 (77/30)
Final drive: Chain
Secondary reduction ratio: 2.947 (56/19)
Transmission type:
Constant mesh 5-speed
Gear ratio: 1st:
2.357 (33/14)
2nd: 1.556 (28/18)
3rd: 1.190 (25/21)
4th: 0.917 (22/24)
5th: 0.778 (21/27)
Chassis:
Frame type:Semi double cradle
Caster angle: 27.7 
Trail:
111 mm (4.4 in)
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