engine YAMAHA SR400 2014 Owner's Manual

OPERATION AND IMPORTANT RIDING POINTS
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r/min.
1600 km (1000 mi) and beyond
The vehicle can now be operated nor-
mally.
NOTICE
ECA10311

Keep the engine speed out of
the tachometer red zone.

If any engine trouble should oc-
cur during the engine break-in
period, immediately have a
Yamaha dealer check the vehi-cle.
EAU17214
ParkingWhen parking, stop the engine, and
then remove the key from the main
switch.
WARNING
EWA10312

Since the engine and exhaust
system can become very hot,
park in a place where pedestri-
ans or children are not likely to
touch them and be burned.

Do not park on a slope or on soft
ground, otherwise the vehicle
may overturn, increasing the
risk of a fuel leak and fire.

Do not park near grass or other
flammable materials whichmight catch fire.
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PERIODIC MAINTENANCE AND ADJUSTMENT
EAU17245
Periodic inspection, adjustment, and lu-
brication will keep your vehicle in the
safest and most efficient condition pos-
sible. Safety is an obligation of the vehi-
cle owner/operator. The most important
points of vehicle inspection, adjust-
ment, and lubrication are explained on
the following pages.
The intervals given in the periodic
maintenance charts should be simply
considered as a general guide under
normal riding conditions. However, de-
pending on the weather, terrain, geo-
graphical location, and individual use,
the maintenance intervals may need to
be shortened.
WARNING
EWA10322
Failure to properly maintain the ve-
hicle or performing maintenance ac-
tivities incorrectly may increase
your risk of injury or death during
service or while using the vehicle. If
you are not familiar with vehicle ser-
vice, have a Yamaha dealer performservice.
WARNING
EWA15123
Turn off the engine when performing
maintenance unless otherwise
specified.
A running engine has moving
parts that can catch on body
parts or clothing and electrical
parts that can cause shocks or
fires.

Running the engine while ser-
vicing can lead to eye injury,
burns, fire, or carbon monoxide
poisoning – possibly leading to
death. See page 1-2 for more in-
formation about carbon monox-ide.WARNING
EWA15461
Brake discs, calipers, drums, and
linings can become very hot during
use. To avoid possible burns, let
brake components cool beforetouching them.
EAU17303
Emission controls not only function to
ensure cleaner air, but are also vital to
proper engine operation and maximum
performance. In the following periodic
maintenance charts, the services relat-
ed to emissions control are grouped
separately. These services require
specialized data, knowledge, and
equipment. Maintenance, replacement,
or repair of the emission control devic-
es and systems may be performed by
any repair establishment or individual
that is certified (if applicable). Yamaha
dealers are trained and equipped to
perform these particular services.
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PERIODIC MAINTENANCE AND ADJUSTMENT
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EAU46862
TIP
The annual checks must be performed every year, except if a kilometer-based maintenance, or for the UK, a
mileage-based maintenance, is performed instead.

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.
EAU46911
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. 
2 Spark plug Check condition.
Clean and regap.


3 *Valves Check valve clearance.
Adjust. 
4 *Fuel injection Check engine idle speed. 
5 *Muffler and exhaust
pipe Check the screw clamp(s) for
looseness. 
6 *Air induction
system Check the air cut-off valve, reed
valve, and hose for damage.
Replace any damaged parts if necessary. 
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PERIODIC MAINTENANCE AND ADJUSTMENT
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EAU59350
TIP
Air filter
This model’s air intake system is equipped with a disposable oil-coated paper element. The air filter element cannot
be cleaned with compressed air, it must be replaced.
The air filter element needs to be replaced more fr equently when riding in unusually wet or dusty areas.

Hydraulic brake service
After disassembling the brake master cylinder and caliper, always change the fluid. Regularly check the brake fluid
level and fill the reservoir as required.
Every two years replace the internal components of the brake master cylinder and caliper, and change the brake fluid. Replace the brake hose every four years and if cracked or damaged.
23 Engine oil Change.
Check oil level and vehicle for oil
leakage. 
24 Engine oil filter
element Replace.

25 *Front and rear brake
switches Check operation.

26 Moving parts and
cables Lubricate.

27 *Throttle grip Check operation.
Check throttle grip free play, and
adjust if necessary.
Lubricate cable and grip housing. 
28 *Lights, signals and
switches Check operation.
Adjust headlight beam.

NO. 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)
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PERIODIC MAINTENANCE AND ADJUSTMENT
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EAU19605
Checking the spark plugThe 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).
TIPIf 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 checkthe 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
1. Spark plug cap
1
1. Spark plug wrench
1
Specified spark plug: NGK/BPR6ES1. Spark plug gapSpark plug gap:0.7–0.8 mm (0.028–0.031 in)
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PERIODIC MAINTENANCE AND ADJUSTMENT
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12 spark plug wrench, and then tight-
en it to the specified torque.
TIPIf 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 speci-fied torque as soon as possible.
3. Install the spark plug cap.
EAU59622
Engine oil and oil filter
elementThe engine oil level should be checked
before each ride. In addition, the oil
must be changed and the oil filter ele-
ment replaced at the intervals specified
in the periodic maintenance and lubri-
cation chart.
To check the engine oil level1. Start the engine, warm it up for several minutes, and then turn it
off.
2. On a level surface, place the vehi- cle on the centerstand.
3. Wait a few minutes until the oil set- tles. Remove the engine oil filler
cap, wipe the dipstick clean, insert
it back into the oil filler hole (with-
out screwing it in), and then re-
move it again to check the oil level.
WARNING! Never remove the
engine oil filler cap after
high-speed operation, other-
wise hot engine oil could spout
out and cause damage or injury.
Always let the engine oil cool
down sufficiently before remov- ing the oil filler cap.
[EWA17640]
TIPThe engine oil should be between theminimum and maximum level marks.
4. If the engine oil is below the mini- mum level mark, add sufficient oil
of the recommended type to raise
it to the correct level.
5. Install the oil filler cap.
Tightening torque: Spark plug:25 Nm (2.5 m·kgf, 18 ft·lbf)
1. Engine oil filler cap
2. Dipstick
3. Maximum level mark
4. Minimum level mark
3
4
12
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PERIODIC MAINTENANCE AND ADJUSTMENT
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To change the engine oil (with or
without oil filter element replace-
ment)
1. Start the engine, warm it up for several minutes, and then turn it
off.
2. Place an oil pan under the engine to collect the used oil.
3. Loosen the oil filter element cover bleed bolt and oil filter element
drain bolt.
4. Remove the engine oil drain bolt and its gasket to drain the oil from
the crankcase. 5. Remove the engine oil filler cap,
the engine oil tank drain bolt and
its gasket to drain the oil from the
oil tank. 6. Remove the oil filter element drain
bolt to drain the oil from the oil filter
element.
TIPSkip steps 7–9 if the oil filter element isnot being replaced.
7. Remove the oil filter element cover by removing the bolts.
8. Remove and replace the oil filter element and O-rings.TIPMake sure that the O-rings are properlyseated.
1. Oil filter element cover bleed bolt
2. Oil filter element drain bolt
1
2
1. Gasket
2. Engine oil drain bolt (crankcase)
1. Engine oil drain bolt (oil tank)
2. Gasket
21
21
1. Oil filter element drain bolt
2. Oil filter element cover bolt
2
1
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PERIODIC MAINTENANCE AND ADJUSTMENT
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12 9. Install the oil filter element cover by
installing the bolts.
10. Install the oil filter element drain bolt.
11. Tighten the oil filter element cover bolts and the oil filter element drain
bolt to their specified torques.
12. Tighten the oil filter element cover bleed bolt to the specified torque. 13. Install the engine oil drain bolts
and their new gasket, and then
tighten the bolts to the specified
torques.
14. Add the specified amount of the recommended engine oil, and then
install and tighten the oil filler cap.
TIPBe 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.
15. 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.
16. 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.
1. Oil filter element cover
2. O-ring
3. Oil filter elementTightening torques:Oil filter element cover bolt:10 Nm (1.0 m·kgf, 7.2 ft·lbf)
Oil filter element drain bolt:
10 Nm (1.0 m·kgf, 7.2 ft·lbf)
2
1
3
Tightening torque:Oil filter element cover bleed bolt:5 Nm (0.5 m·kgf, 3.6 ft·lbf)
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:
Without oil filter element replace-
ment:2.00 L (2.11 US qt, 1.76 Imp.qt)
With oil filter element replacement: 2.10 L (2.22 US qt, 1.85 Imp.qt)
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PERIODIC MAINTENANCE AND ADJUSTMENT
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
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 thespecified torque.
EAU52031
Replacing the air filter elementThe 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. Bleed boltTightening torque: Bleed bolt: 18 Nm (1.8 m·kgf, 13 ft·lbf)
1
1. Screw
2. Air filter case cover
1
2
1
1. Air filter element
1
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PERIODIC MAINTENANCE AND ADJUSTMENT
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EAU44735
Checking the engine idling
speedCheck the engine idling speed and, if
necessary, have it corrected by a
Yamaha dealer.
EAU21385
Checking the thrott le grip free
playThe throttle grip free play should mea-
sure 3.0–5.0 mm (0.12–0.20 in) at the
inner edge of the throttle grip. Periodi-
cally check the throttle grip free play
and, if necessary, have a Yamaha
dealer adjust it.
EAU21402
Valve clearanceThe 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.
Engine idling speed: 1200–1400 r/min
1. Throttle grip free play
1
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