2017 YAMAHA YS125 crank

Instrument and control functions
3-6
3
EAU12713
Start switch “ ”
Push this switch to crank the engine
with the starter. See page 5-1 for start-
ing instructions prior to starting the en-
gine.
EAU12822
Clutch leverThe clutch lever is located on the left
side of the handlebar. To disengage
the clutch, pull the lever toward the
handlebar grip. To engage the clutch,
release the lever. The lever should be
pulled rapidly and released slowly for
smooth clutch operation.
The clutch lever is equipped with a
clutch switch, which is part of the igni-
tion circuit cut-off system. (See page
3-13.)
EAU12872
Shift pe dalThe shift pedal is located on the left
side of the motorcycle and is used in
combination with the clutch lever when
shifting the gears of the 5-speed con-
stant-mesh transmission equipped on
this motorcycle.
1. Clutch lever
1
1. Shift pedal
1
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Operation and important rid ing points
5-1
5
EAU15952
Read the Owner’s Manual carefully to
become familiar with all controls. If
there is a control or function you do not
understand, ask your Yamaha dealer.
WARNING
EWA10272
Failure to familiarize yourself with
the controls can lead to loss of con-
trol, which coul d cause an acci dent
or injury.
EAUM3150
TIPThis model is equipped with a lean an-
gle sensor to stop the engine in case of
a turnover. To start the engine after a
turnover, be sure to turn the main
switch to “ ” and then to “ ”. Failing
to do so will prevent the engine from
starting even though the engine will
crank when pushing the start switch.
EAU78350
Startin g the en gineIn order for the ignition circuit cut-off
system to enable starting, one of the
following conditions must be met:
 The transmission is in the neutral
position.
 The transmission is in gear with
the clutch lever pulled and the
sidestand up.
See page 3-13 for more informa-
tion.
1. Turn the key to “ ”. The engine trouble warning light
should come on for a few sec-
onds, then go off.NOTICE
ECA23970
If the warnin g li ght does not come
on initially when the key is turne d
to “ ”, or if the warnin g li ght re-
mains on, see pag e 3-2 for the warn-
in g lig ht circuit check.2. Shift the transmission into the
neutral position. The neutral indi-
cator light should come on. If not,
ask a Yamaha dealer to check the
electrical circuit.
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Operation and important ri din g points
5-2
5
3. Start the engine by pushing the
start switch.
If the engine fails to start when us-
ing the start switch, release it, wait
a few seconds, and then try again.
Each starting attempt should be
as short as possible to preserve
the battery. Do not crank the en-
gine more than 10 seconds on any
one attempt.
NOTICE
ECA11043
For maximum en gine life, never ac-
celerate har d when the en gine is
col d!
EAU16673
Shiftin gShifting gears lets you control the
amount of engine power available for
starting off, accelerating, climbing hills,
etc.
The gear positions are shown in the il-
lustration.TIPTo shift the transmission into the neu-
tral position, press the shift pedal down
repeatedly until it reaches the end of its
travel, and then slightly raise it.
NOTICE
ECA10261
Even with the transmission in
the neutral position, d o not
coast for lon g period s of time
with the en gine off, an d d o not
tow the motorcycle for lon g d is-
tances. The transmission is
properly lu bricated only when
the en gine is runnin g. Ina de-
quate lu brication may d amage
the transmission.
 Always use the clutch while
chan gin g g ears to avoi d d am-
a g in g the en gine, transmission,
an d d rive train, which are not
d esi gne d to withstan d the
shock of force d shiftin g.
1. Shift pedal
2. Neutral position
1
N
2 3
4
5
1
2
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Periodic maintenance an d a djustment
6-12
6
ficiently
before removin g the oil
filler cap.
[EWA17640]
NOTICE: Do not
operate the vehicle until you
know that the en gine oil level is
sufficient.
[ECA10012]
TIPThe engine oil should be between the
minimum 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. Check the O-ring for damage, and replace it if necessary.
6. Install and tighten the engine oil filler cap.
To chan ge the en gine 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. Remove the engine oil filler cap, the engine oil drain bolt and its
gasket to drain the oil from the
crankcase.
TIPSkip steps 4–6 if the oil filter element is
not being replaced.4. Remove the oil filter element coverby removing the bolts.
1. Engine oil filler cap
1. O-ring
2. Engine oil dipstick
3. Maximum level mark
4. Minimum level mark
1
4 321
1. Engine oil drain bolt
2. Gasket
1. Bolt
2. Oil filter element cover
12
1
2
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Periodic maintenance an d a djustment
6-13
6 5. Remove and replace the oil filter
element and O-ring.
6. Install the oil filter element cover by installing the bolts, then tight-
ening them to the specified
torque.
TIPMake sure that the O-ring is properly
seated.7. Install the engine oil drain bolt andits new gasket, and then tighten
the bolt to the specified torque. 8. Refill with the specified amount of
the recommended engine oil.
NOTICE
ECA11621
In or der to prevent clutch slip-
pa ge (since the en gine oil also
lu bricates the clutch), do not
mix any chemical additives. Do
not use oils with a diesel speci-
fication of “CD” or oils of a hi gh-
er quality than specifie d. In
a ddition, do not use oils la beled
“ENERGY CONSERVING II” or
hi gher.
 Make sure that no forei gn mate-
rial enters the crankcase.
9. Check the O-ring for damage, and replace it if necessary.
10. Install and tighten the engine oil filler cap.NOTICE
ECA10441
After chan gin g the en gine oil, b e
sure to check the oil pressure as de-
scri bed b elow.To check the oil pressure
1. Remove cowling A. (See page 6-8.)
2. Remove the Y.R.C.S. (Yamaha Ram-Air Cooling System) cap.
(See page 6-10.)
1. Oil filter element
2. O-ringTightenin g torque:
Oil filter element cover bolt: 10 N·m (1.0 kgf·m, 7.2 lb·ft)
2 1
Ti
ghtenin g torque:
Engine oil drain bolt:
20 N·m (2.0 kgf·m, 14 lb·ft)
Recommen ded en gine oil:
See page 8-1.
Oil quantity:
Oil change:1.00 L (1.06 US qt, 0.88 Imp.qt)
With oil filter removal:
1.10 L (1.16 US qt, 0.97 Imp.qt)
1. Engine oil filler cap
2. O-ring
21
UBT4E0E0.book Page 13 Thursday, November 17, 2016 10:55 AM

Motorcycle care and stora ge
7-1
7
EAU37834
Matte color cautionNOTICE
ECA15193
Some mo dels are equipped with
matte colored finished parts. Be
sure to consult a Yamaha dealer for
a d vice on what prod ucts to use be-
fore cleanin g the vehicle. Usin g a
b rush, harsh chemical pro ducts or
cleanin g compoun ds when cleanin g
these parts will scratch or damag e
their surface. Wax also shoul d not
b e applie d to any matte colored fin-
ishe d parts.
EAU26005
CareWhile 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 mo-
torcycle. Frequent and proper care
does not only comply with the terms of
the warranty, but it will also keep your
motorcycle looking good, extend its
life and optimize its performance.
Before cleanin g
1. Cover the muffler outlet with a plastic bag after the engine has
cooled down.
2. Make sure that all caps and cov- ers as well as all electrical cou-
plers 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
degreaser off with water.
Cleanin g
NOTICE
ECA10773
Avoi d usin g stron g aci dic wheel
cleaners, especially on spoked
wheels. If such pro ducts are
use d on har d-to-remove dirt, do
not leave the cleaner on the af-
fected area any lon ger than in-
structed . Also, thorou ghly rinse
the area off with water, immed i-
ately dry it, an d then apply a cor-
rosion protection spray.
 Improper cleanin g can d amage
plastic parts (such as cowlin gs,
panels, win dshiel ds, hea dlig ht
lenses, meter lenses, etc.) an d
the mufflers. Use only a soft,
clean cloth or spon ge with wa-
ter to clean plastic. However, if
the plastic parts cannot be thor-
ou ghly cleaned with water, di-
lute d mil d d eter gent with water
may be used . Be sure to rinse
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Consumer information
9-1
9
EAU53562
Id entification num bersRecord the vehicle identification num-
ber, engine serial number, and the
model label information in the spaces
provided below. These identification
numbers are needed when registering
the vehicle with the authorities in your
area and when ordering spare parts
from a Yamaha dealer.
VEHICLE IDENTIFICATION NUMBER:
ENGINE SERIAL NUMBER:
MODEL LABEL INFORMATION:
EAU26401
Vehicle i dentification num ber
The vehicle identification number is
stamped into the steering head pipe.
Record this number in the space pro-
vided.TIPThe vehicle identification number is
used to identify your motorcycle and
may be used to register your motorcy-
cle with the licensing authority in your
area.
EAU26442
En gine serial num ber
The engine serial number is stamped
into the crankcase.
EAU36981
Mo del la bel
1. Vehicle identification number
1
1. Engine serial number
1. Model label
1
1
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