2020 YAMAHA YFZ50 brake

EBU17421
TABLE OF CONTENTS
LOCATION OF THE WARNING AND
SPECIFICATION LABELS .............................. 1-1
SAFETY INFORMATION ................................ 2-1
DESCRIPTION................................................ 3-1Left view ...................................................... 3-1
Right view.................................................... 3-1
Controls and instruments............................ 3-2
INSTRUMENT AND CONTROL
FUNCTIONS ................................................... 4-1 Main switch ................................................. 4-1
Handlebar switches .................................... 4-1
Engine stop switch with lanyard ................. 4-2
Throttle lever ............................................... 4-3
Speed limiter ............................................... 4-3
Front brake lever ......................................... 4-5
Rear brake lever .......................................... 4-6
Parking brake .............................................. 4-6
Kickstarter ................................................... 4-7
Fuel tank cap .............................................. 4-8
Fuel ............................................................. 4-9
Fuel cock................................................... 4-10 Starter (choke) ......................................... 4-12
Seat .......................................................... 4-13
Rear shock absorber ................................ 4-13
PRE-OPERATION CHECKS .......................... 5-1 Fuel ............................................................. 5-3
Engine oil .................................................... 5-3
Transmission oil .......................................... 5-3
Front and rear brakes ................................. 5-3
Throttle lever ............................................... 5-3
Drive chain .................................................. 5-3
Tires ............................................................ 5-3
Chassis fasteners ....................................... 5-6
Instruments and switches........................... 5-6
OPERATION .................................................. 6-1 Starting a cold engine................................. 6-1
Starting a warm engine............................... 6-3
Engine break-in........................................... 6-3
Parking........................................................ 6-3
Parking on a slope ...................................... 6-4
Accessories and loading ............................ 6-5UBW463E0.book Page 1 Monday, January 28, 2019 10:22 AM

RIDING YOUR ATV ........................................ 7-1GETTING TO KNOW YOUR ATV ................ 7-2
RIDE WITH CARE AND GOOD JUDGMENT .............................................. 7-2
BE CAREFUL WHERE YOU RIDE ............... 7-9
TURNING YOUR ATV................................ 7-12
CLIMBING UPHILL ................................... 7-13
RIDING DOWNHILL .................................. 7-16
CROSSING A SLOPE................................ 7-17
CROSSING THROUGH SHALLOW WATER .................................................... 7-18
RIDING OVER ROUGH TERRAIN ............. 7-20
SLIDING AND SKIDDING .......................... 7-20
WHAT TO DO IF... ..................................... 7-21
WHAT TO DO... ......................................... 7-22
PERIODIC MAINTENANCE AND
ADJUSTMENT................................................ 8-1 Owner’s Manual and tool kit ....................... 8-2
Periodic maintenance chart: Emission control system .......................................... 8-3
Periodic maintenance chart: General maintenance and lubrication..................... 8-5
Removing and installing the panel .............. 8-9
Checking the spark plug ............................. 8-9
Engine oil................................................... 8-11
Why Yamalube .......................................... 8-14 Transmission oil ........................................ 8-15
Cleaning the air filter element ................... 8-16
Cleaning the spark arrester ...................... 8-19
Adjusting the carburetor ........................... 8-20
Adjusting the engine idling speed ............ 8-20
Adjusting the throttle lever free play ......... 8-22
Valve clearance......................................... 8-22
Brakes....................................................... 8-22
Checking the front and rear brake
shoes ...................................................... 8-23
Adjusting the front brake lever free play... 8-24
Adjusting the rear brake lever free play .... 8-26
Drive chain slack....................................... 8-26
Cleaning and lubricating the drive chain ....................................................... 8-29
Checking and lubricating the cables ........ 8-29
Checking and lubricating the front and rear brake levers ..................................... 8-30
Checking the wheel hub bearings ............ 8-30
Lubricating the front arm pivots ............... 8-31
Lubricating the front knuckle pivots ......... 8-31
Lubricating the steering shaft ................... 8-32
Battery ...................................................... 8-32
Replacing the fuse .................................... 8-35
Removing a wheel .................................... 8-36
Installing a wheel ...................................... 8-36
Troubleshooting........................................ 8-37UBW463E0.book Page 2 Monday, January 28, 2019 10:22 AM

2-3
2surfaces. Shift your weight to the uphill side of
the ATV. Never attempt to turn the ATV around
on any hill until you have mastered the turning
technique described in this manual on level
ground. Avoid crossing the side of a steep hill if
possible.
 Always use proper procedures if you stall or roll
backwards when climbing a hill. If you stall or
roll backwards, follow the special procedure for
braking described in this manual. Dismount on
the uphill side or to a side if pointed straight up-
hill. Turn the ATV around and remount, following
the procedure described in this manual.
 Always check for obstacles before operating in
a new area.
 Never attempt to operate over large obstacles,
such as large rocks or fallen trees. Always follow
proper procedures when operating over obsta-
cles as described in this manual.
 Always be careful when skidding or sliding.
Learn to safely control skidding or sliding by
practicing at low speeds and on level, smooth
terrain. On extremely slippery surfaces, such as
ice, go slowly and be very cautious in order to
reduce the chance of skidding or sliding out of
control. 
Never operate an ATV in fast flowing water or in
water deeper than that recommended in this
manual. Remember that wet brakes may have
reduced stopping ability. Test your brakes after
leaving water. If necessary, apply them several
times to let friction dry out the linings.
 Always use the size and type of tires specified in
this manual.
 Always maintain proper tire pressure as de-
scribed in this manual.
 Never exceed the stated load capacity for an
ATV. Cargo should be properly distributed and
securely attached. Reduce speed and follow in-
structions in this manual for carrying cargo or
pulling a trailer. Allow greater distance for brak-
ing.
 Do not operate your ATV during darkness un-
less it is equipped with a properly functioning
headlight. Off-road riding is inherently danger-
ous and additionally, off-road trails do not have
streetlights to guide you.
 Never maintain an ATV without proper knowl-
edge. Contact an authorized ATV dealer to in-
form you on basic ATV maintenance. Certain
maintenance can only be carried out by certified
staff.
UBW463E0.book Page 3 Monday, January 28, 2019 10:22 AM

3-2
3
EBU17715Controls and instruments1. Rear brake lever
2. Handlebar switches
3. Parking brake lock plate
4. Front brake lever
5. Throttle lever
6. Main switch
7. Starter (choke) lever
12376 54
UBW463E0.book Page 2 Monday, January 28, 2019 10:22 AM

4-5
43. Tighten the screws.
4. Install the panel.
TIPStore the engine speed limiter plate with the own-
er’s manual so that it is readily available whenever
you want to reduce top engine speed.
EBU18393Front brake leverThe front brake lever is located on the right han-
dlebar. To apply the front brake, pull the brake le-
ver toward the handlebar grip.
1. Screw
2. Engine speed limiter plate
21
1. Front brake lever
1
UBW463E0.book Page 5 Monday, January 28, 2019 10:22 AM

4-6
4
EBU18403Rear brake leverThe rear brake lever is located on the left handle-
bar. To apply the rear brake, pull the brake lever
toward the handlebar grip.EBU18462Parking brakeUse the parking brake before starting the engine
or after parking the ATV, especially on a slope. Ap-
ply the rear brake lever and push down the lock
plate to apply the parking brake. Squeeze the rear
brake lever to release the parking brake.
WARNING
EWB00221Always set the parking brake before starting
the engine. The ATV could start moving un-
expectedly if the parking brake is not ap-
plied. This could cause loss of control or a
collision.
 Always be sure you have released the park-
ing brake before you begin to ride. The brake
could overheat if you ride the ATV without re-
leasing the parking brake. You could lose
1. Rear brake lever
1
1. Parking brake lock plate
1
UBW463E0.book Page 6 Monday, January 28, 2019 10:22 AM

4-7
4braking performance which could cause an
accident. You could also wear out the brakes
prematurely.
EBU33893KickstarterUse the kickstarter to start the engine when the
battery voltage is low.
1. Remove the seat (page 4-13), and then re- move the kickstarter lever.
2. Remove the kickstarter lever cap. 3. Install the kickstarter lever.
4. Move the kickstarter lever down lightly with
your foot until the gears engage, and then
push it down smoothly but forcefully.1. Kickstarter lever
1
1. Kickstarter lever cap
1
UBW463E0.book Page 7 Monday, January 28, 2019 10:22 AM

5-1
5
EBU19203
PRE-OPERATION CHECKS
EBU19226Inspect your vehicle each time you use it to make sure the vehicle is in safe operating condition. Always
follow the inspection and maintenance procedures and schedules described in the Owner’s Manual.
WARNING
EWB00482Failure to inspect or maintain the vehicle properly increases the possibility of an accident or equip-
ment 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:
ITEMROUTINE PAGE
Fuel • Check fuel level in fuel tank,
and add recommended fuel if neces-
sary.
• Check fuel line for leakage. Correct if necessary. 4-9, 5-3
Engine oil • Check oil level in engine, and add recommended oil to specified
level if necessary.
• Check ATV for oil leakage. Correct if necessary. 5-3, 8-11
Transmission oil • Check ATV for oil leakage. Correct if necessary. 5-3, 8-15
Front brake • Check operation, and correct if necessary.
• Lubricate cable if necessary.
• Check lever free play, and adjust if necessary. 5-3, 8-23, 8-24
Rear brake • Check operation, and correct if necessary.
• Lubricate cable if necessary.
• Check lever free play, and adjust if necessary. 5-3, 8-23, 8-26
UBW463E0.book Page 1 Monday, January 28, 2019 10:22 AM