2021 YAMAHA YFZ50 ignition

5-1
5
EBU17739
INSTRUMENT AND CONTROL FUNCTIONS
EBU33850Main switchThe positions of the main switch are as follows:
ON
All electrical systems are supplied with power, and
the engine can be started. The key cannot be re-
moved.
OFF
All electrical systems are off. The key can be re-
moved.
EBU18068Handlebar switchesEBU18081Engine stop switch “ / ”
Set this switch to “ ” before starting the engine.
The engine stop switch controls the ignition and
stops the engine when it is running. Use this
switch to stop the engine in an emergency situa-
tion. The engine will not start or run when this
switch is set to “ ”.
ON
OFF
1. Engine stop switch ´ L

5-9
5of sparks, open flames, or other sources of
ignition such as the pilot lights of water heat-
ers and clothes dryers.
2. Do not overfill the fuel tank. When refueling, be sure to insert the pump nozzle into the fuel
tank filler hole. Stop filling when the fuel
reaches the bottom of the filler tube. Because
fuel expands when it heats up, heat from the
engine or the sun can cause fuel to spill out of
the fuel tank. 3. Wipe up any spilled fuel immediately.
NOTICE: Immediately wipe off spilled fuel
with a clean, dry, soft cloth, since fuel may
deteriorate painted surfaces or plastic
parts.
[ECB00982]
4. Turn the fuel tank cap fully clockwise to make sure it is securely closed.EBU38650FuelMake sure there is sufficient gasoline in the tank
before starting off. Refuel if necessary.
WARNING
EWB02532Gasoline is poisonous and can cause injury or
death. Handle gasoline with care. Never siphon
gasoline by mouth. If you should swallow some
gasoline or inhale a lot of gasoline vapor, or get
some gasoline in your eyes, see your doctor
immediately. If gasoline spills on your skin,
wash with soap and water. If gasoline spills on
your clothing, change your clothes.
1. Maximum fuel level
2. Fuel tank filler tube
2 1
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9-33
9
TIPWear gloves and eye protection in a ventilated
area away from sparks and open flames. Wash
hands after handling.
 It is recommended to have the battery serviced
by a Yamaha dealer.
WARNING
EWB02161Battery electrolyte is poisonous and danger-
ous, as it contains sulfuric acid, which can cau-
se severe burns. Avoid contact with skin, eyes
or clothing. Always shield your eyes when
working near batteries.
Antidote:
EXTERNAL: Flush with water.
INTERNAL: Drink large quantities of water or
milk. Follow with milk of magnesia, beaten egg
or vegetable oil. Call a physician immediately.
EYES: Flush with water for 15 minutes and get
prompt medical attention.
Batteries produce explosive gases. Keep
sparks, flame, cigarettes or other sources of
ignition away. Ventilate when charging or using
in an enclosed space. KEEP OUT OF REACH OF CHILDREN.
To remove the battery
1. Remove panel A. (See page 9-9.)
2. Unhook the battery band.
3. Disconnect the negative battery lead first, then the positive battery lead by removing
their bolt. NOTICE: When removing the bat-
tery, the main switch must be off, and the
negative lead must be disconnected be-
fore the positive lead.
[ECB01002]
1. Positive battery lead (red)
2. Negative battery lead (black)
3. Battery
4. Battery band2 4
3
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9-37
92. Lower the ATV to the ground.
3. Tighten the wheel bolts to the specified
torques.
EBU25721TroubleshootingAlthough Yamaha ATVs receive a thorough in-
spection before shipment from the factory, trouble
may occur during operation. Any problem in the
fuel, compression, or ignition systems, for exam-
ple, can cause poor starting and loss of power.
The following troubleshooting chart represents a
quick and easy procedure for checking these vital
systems yourself. However, should your ATV re-
quire any repair, take it to a Yamaha dealer, whose
skilled technicians have the necessary tools, ex-
perience, and know-how to service the ATV prop-
erly.
Use only genuine Yamaha replacement parts. Im-
itation parts may look like Yamaha parts, but they
are often inferior, have a shorter service life and
can lead to expensive repair bills.
WARNING
EWB02281Do not smoke when checking the fuel system.
Fuel can ignite or explode, causing severe inju-
ry or property damage. Make sure there are no
open flames or sparks in the area, including pi-
lot lights from water heaters or furnaces.
1. Arrow mark
2. Forward rotating direction
3. Wheel boltTightening torques:Front wheel bolt:45 N·m (4.5 kgf·m, 33 lb·ft)
Rear wheel bolt: 45 N·m (4.5 kgf·m, 33 lb·ft)3
1
2
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9-38
9
EBU25812Troubleshooting chart
Check the fuel level in
the fuel tank.1. Fuel
There is enough fuel.There is no fuel.
Check the battery.
Supply fuel.
The engine does not start.
Check the battery.
The engine does not start.
Check the ignition.
Operate the electric starter.4. Compression
There is compression.
There is no compression.
The engine does not start. Have a Yamaha dealer check the ATV.Have a Yamaha dealer check the ATV.
Remove the spark plug
and check the electrodes.3. Ignition
Wipe off with a dry cloth and correct the
spark plug gap, or replace the spark plug.
Have a Yamaha dealer check the ATV.
The engine does not start.
Check the compression.
Operate the electric starter.2. Battery
The engine turns over
quickly.
The engine turns over
slowly.
The battery is good.Check the battery lead connections.
Recharge the battery or use the
kickstarter.
DryWet
Open the throttle halfway and try
starting the engine.
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11-4
11
Electrical system:System voltage:12 V
Ignition system:
CDI
Charging system: AC magnetoBattery:Model:
GTX5L-BS
Voltage, capacity: 12 V, 4.0 AhFuses:Main fuse:
7.5 AEBU30403Noise and vibration levels statement (for Eu-
rope)
The figures quoted are emission levels and are not
necessarily safe working levels. Whilst there is a
correlation between the emission and exposure
levels, this cannot be used reliably to determine
whether or not further precautions are required.
Factors that influence the actual level of exposure
of work-force include the characteristics of the
work room, the other sources of noise, etc. i.e. the
number of machines and other adjacent process- es, and the length of time for which an operator is
exposed to the noise. Also the permissible expo-
sure level can vary from country. This information,
however, will enable the user of the machine to
make a better evaluation of the hazard and risk.UBW464E0.book Page 4 Thursday, January 23, 2020 2:42 PM