2019 YAMAHA YZF-R125 check engine

Instrument and control functions
3-21
3
EAU66730
Ignition circuit cut-off system
The ignition circuit cut-off system
(comprising the sidestand switch,
clutch switch and neutral switch) has
the following functions.
It prevents starting when the
transmission is in gear and the
sidestand is up, but the clutch le-
ver is not pulled.
It prevents starting when the
transmission is in gear and the
clutch lever is pulled, but the side-
stand is still down.
It cuts the running engine when
the transmission is in gear and the
sidestand is moved down.
Periodically check the operation of the
ignition circuit cut-off system accord-
ing to the following procedure.
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Instrument and control functions
3-22
3
With the engine turned off:
1. Move the sidestand down.
2.
Make sure that the engine stop switch
is set to “ ”.
3. Turn the key on.
4. Shift the transmission into the neutral
position.
5. Push the start switch.
Does the engine start?
With the engine still running:
6. Move the sidestand up.
7. Keep the clutch lever pulled.
8. Shift the transmission into gear.
9. Move the sidestand down.
Does the engine stall?
After the engine has stalled:
10. Move the sidestand up.
11. Keep the clutch lever pulled.
12. Push the start switch.
Does the engine start?
The system is OK. The motorcycle can
be ridden.
The neutral switch may not be working
correctly.
The motorcycle should not be ridden
until checked by a Yamaha dealer.
The sidestand switch may not be
working correctly.
The motorcycle should not be ridden
until checked by a Yamaha dealer.
The clutch switch may not be working
correctly.
The motorcycle should not be ridden
until checked by a Yamaha dealer.
WARNING
If a malfunction is noted, have a
Yamaha dealer check the system
before riding.
YES NO
YES NO
YES NO
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For your safety – pre-operation checks
4-1
4
EAU63441
Inspect your vehicle each time you use it to make sure the vehicle is in safe oper-
ating condition. Always follow the inspection and maintenance procedures and
schedules described in the Owner’s Manual.
WARNING
EWA11152
Failure to inspect or maintain the vehicle properly increases the possibility
of an accident or equipment damage. Do not operate the vehicle if you find
any problem. If a problem cannot be corrected by the procedures provided
in this manual, have the vehicle inspected by a Yamaha dealer.
Before using this vehicle, check the following points:
ITEM CHECKS PAGE
Fuel• Check fuel level in fuel tank.
• Refuel if necessary.
• Check fuel line for leakage.
• Check fuel tank overflow hose for obstructions, cracks
or damage, and check hose connection.3-16,
3-18
Engine oil• Check oil level in engine.
• If necessary, add recommended oil to specified level.
• Check vehicle for oil leakage.6-10
Coolant• Check coolant level in reservoir.
• If necessary, add recommended coolant to specified
level.
• Check cooling system for leakage.6-13
Front brake• Check operation.
• If soft or spongy, have Yamaha dealer bleed hydraulic
system.
• Check brake pads for wear.
• Replace if necessary.
• Check fluid level in reservoir.
• If necessary, add specified brake fluid to specified level.
• Check hydraulic system for leakage.6-22,
6-23
Rear brake• Check operation.
• If soft or spongy, have Yamaha dealer bleed hydraulic
system.
• Check brake pads for wear.
• Replace if necessary.
• Check fluid level in reservoir.
• If necessary, add specified brake fluid to specified level.
• Check hydraulic system for leakage.6-22,
6-23
Clutch• Check operation.
• Lubricate cable if necessary.
• Check lever free play.
• Adjust if necessary.6-20
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Operation and important riding points
5-2
5
EAUM4021
Starting the engine
Under normal conditions, shift the
transmission into neutral before start-
ing the engine. To start the engine with
the transmission in gear, the sidestand
must be up and the clutch lever pulled.
To start the engine
1. Set the engine stop switch to the
run position, and turn the main
switch to the on position.
2. Confirm the following lights come
on for a few seconds and then go
off.
Engine trouble warning light
Coolant warning light
Shift timing indicator light
TIP
The ABS warning light should go
off after reaching a speed of 10
km/h (6 mi/h) or higher.
The neutral position indicator light
should be on when the transmis-
sion is in neutral.
NOTICE
ECA24110
If a warning or indicator light does
not work as described above, have a
Yamaha dealer check the vehicle.
3. Shift the transmission into neutral.
4. Push the start switch to crank the
engine with the starter.
Release the start switch when the
engine starts, or after 5 seconds.
Wait 10 seconds before pressing
the switch again to allow battery
voltage to restore.
NOTICE
ECA11043
For maximum engine life, never ac-
celerate hard when the engine is
cold!
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Operation and important riding points
5-5
5 1000 km (600 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
Parking
When 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 which
might catch fire.
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Periodic maintenance and adjustment
6-3
6
EAU71021
TIP
The annual checks must be performed every year, except if a distance-
based maintenance is performed instead.
From 30000 km (17500 mi), repeat the maintenance intervals starting from
6000 km (3500 mi).
Items marked with an asterisk should be performed by a Yamaha dealer as
they require special tools, data and technical skills.
EAU71060
Periodic maintenance chart for the emission control system
NO. ITEM
1*Fuel line• Check fuel hoses for cracks or
damage.
• Replace if necessary.√√√√√
2*Spark plug• Check condition.
• Adjust gap and clean.√√
• Replace.√√
3*Valve clearance• Check and adjust.√√√√
4*Fuel injection• Check engine idle speed.√√√√√√
5*Exhaust system• Check for leakage.
• Tighten if necessary.
• Replace gasket if necessary.√√√√√X 1000 km CHECK OR
MAINTENANCE JOB
X 1000 miODOMETER
READING
ANNUAL CHECK
1 6 12 18 24
0.6 3.5 7 10.5 14
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Periodic maintenance and adjustment
6-6
6
EAU72740
TIP
The air filter needs more frequent service if you are riding in unusually wet or
dusty areas.
Hydraulic brake service
• Regularly check and, if necessary, correct the brake fluid level.
• Every two years change the brake fluid.
• Replace the brake hoses every four years and if cracked or damaged.
25*Rear suspension
relay arm and con-
necting arm pivot-
ing points• Check operation.√√√√
• Lubricate with lithium-soap-
based grease.√√
26 Engine oil• Change (warm engine before
draining).
• Check oil level and vehicle for oil
leakage.At the initial interval and
every 3000 km (1800 mi)
thereafter.√
27Engine oil filter el-
ement• Replace.√√√√√
28*Cooling system• Check coolant level and vehicle
for coolant leakage.√√√√√
• Change. Every 3 years
29*Front and rear
brake switches• Check operation.√√√√√√
30*Moving parts and
cables• Lubricate.√√√√√
31*Throttle grip hous-
ing and cable• Check operation and free play.
• Adjust the throttle cable free
play if necessary.
• Lubricate the throttle grip hous-
ing and cable.√√√√√
32*Lights, signals and
switches• Check operation.
• Adjust headlight beam.√√√√√√ NO. ITEM
X 1000 km CHECK OR
MAINTENANCE JOB
X 1000 mi
ODOMETER
READING
ANNUAL CHECK
16121824
0.63.5710.514
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Periodic maintenance and adjustment
6-9
6
EAU19623
Checking the spark plug
The spark plug is an important engine
component, which should be checked
periodically, preferably by a Yamaha
dealer. Since heat and deposits will
cause any spark plug to slowly erode,
it should be removed and checked in
accordance with the periodic mainte-
nance and lubrication chart. In addi-
tion, the condition of the spark plug
can reveal the condition of the engine.
The porcelain insulator around the
center electrode of the spark plug
should be a medium-to-light tan (the
ideal color when the vehicle is ridden
normally). If the spark plug shows a
distinctly different color, the engine
could be operating improperly. Do not
attempt to diagnose such problems
yourself. Instead, have a Yamaha deal-
er check the vehicle.
If the spark plug shows signs of elec-
trode erosion and excessive carbon or
other deposits, it should be replaced.
Before installing a spark plug, the
spark plug gap should be measured
with a wire thickness gauge and, if
necessary, adjusted to specification.Clean the surface of the spark plug
gasket and its mating surface, and
then wipe off any grime from the spark
plug threads.
TIP
If 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
specified torque as soon as possible.
Specified spark plug:
NGK/MR8E9
1. Spark plug gap
Spark plug gap:
0.8–0.9 mm (0.031–0.035 in)
Tightening torque:
Spark plug:
12.5 N·m (1.25 kgf·m, 9.22 lb·ft)
1
ZAUM0037
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