2021 YAMAHA YFZ50 ABS

EBU17421
TABLE OF CONTENTS
VEHICLE IDENTIFICATION ............................ 1-1Identification numbers ................................ 1-1
LOCATION OF THE WARNING AND
SPECIFICATION LABELS .............................. 2-1
SAFETY INFORMATION ................................ 3-1
DESCRIPTION................................................ 4-1 Left view ...................................................... 4-1
Right view.................................................... 4-1
Controls and instruments............................ 4-2
INSTRUMENT AND CONTROL
FUNCTIONS ................................................... 5-1 Main switch ................................................. 5-1
Handlebar switches .................................... 5-1
Engine stop switch with lanyard ................. 5-2
Throttle lever ............................................... 5-3
Speed limiter ............................................... 5-3
Front brake lever ......................................... 5-5
Rear brake lever .......................................... 5-6
Parking brake .............................................. 5-6
Kickstarter ................................................... 5-7 Fuel tank cap .............................................. 5-8
Fuel ............................................................. 5-9
Fuel cock .................................................. 5-10
Starter (choke) ......................................... 5-12
Seat .......................................................... 5-13
Rear shock absorber ................................ 5-13
PRE-OPERATION CHECKS .......................... 6-1 Fuel ............................................................. 6-3
Engine oil .................................................... 6-3
Transmission oil .......................................... 6-3
Front and rear brakes ................................. 6-3
Throttle lever ............................................... 6-3
Drive chain .................................................. 6-3
Tires ............................................................ 6-3
Chassis fasteners ....................................... 6-6
Instruments and switches........................... 6-6
OPERATION .................................................. 7-1 Starting a cold engine................................. 7-1
Starting a warm engine............................... 7-3
Engine break-in........................................... 7-3
Parking........................................................ 7-3
Parking on a slope ...................................... 7-4UBW464E0.book Page 1 Thursday, January 23, 2020 2:42 PM

4-1
4
EBU17681
DESCRIPTION
EBU17691Left view
EBU17701Right view
1. Fuel tank cap
2. Fuel cock
3. Air filter
4. Engine stop switch with cord (lanyard)
5. Rear shock absorber
6. Kickstarter lever cap
7. Throttle stop screw
12
4
5
3
6
7
1. Spark arrester
2. Reflector
3. Tool kit
4. Fuse
5. Battery
6. Spark plug
7. Engine oil filler cap
8. Transmission oil filler cap1
23
4,5
6
78
UBW464E0.book Page 1 Thursday, January 23, 2020 2:42 PM

5-13
5
EBU36431SeatTo remove the seat
Push down on the rear of the seat and pull the seat
lock lever upward to release the seat lock. Then
pull up at the rear of the seat to remove it.To install the seat
Insert the projections on the front of the seat into
the seat holders, and then push down on the seat
at the rear to lock it in place. Make sure that the
seat is securely fitted.
EBU19027Rear shock absorberThe spring preload can be adjusted to suit the rid-
er’s weight and the riding conditions.
1. Seat
2. Seat lock lever
1
2
1. Projection
2. Seat holder
2
1
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9-6
9
5*Wheels • Check runout and for damage, and replace if nec-
essary. √ √√√
6 *Tires • Check tread depth and for damage, and replace if
necessary.
• Check air pressure and balance, and correct if necessary. √ √√√
7 *Wheel hub bearings • Check for looseness or damage, and replace if
necessary. √ √√√
8 *Front arm pivots • Lubricate with lithium-soap-based grease. √√√
9 Drive chain • Check chain slack and adjust if necessary.
• Check rear wheel alignment and correct if neces-
sary.
• Clean and lubricate. √√√√√
10 *V- b e l t • Check for wear, cracks or other damage, and re-
place if necessary. √ √√√
11 *Chassis fasteners • Make sure that all nuts, bolts, and screws are
properly tightened. √√√√√
12 *Shock absorber as-
semblies • Check operation and correct if necessary.
• Check for oil leakage and replace if necessary.
√√√
13 *Front knuckle piv-
ots • Lubricate with lithium-soap-based grease.
√√√
14 *Steering shaft • Lubricate with lithium-soap-based grease. √√√
NO. ITEM
CHECK OR MAINTENANCE
JOB INITIAL EVERY
Whichev- er comes first month136612
km (mi) 240
(150) 1300
(800) 2500
(1600) 2500
(1600) 5000
(3200)
hours 20 80 160 160 320
UBW464E0.book Page 6 Thursday, January 23, 2020 2:42 PM

10-1
10
EBU25861
CLEANING AND STORAGE
EBU25903CleaningFrequent, thorough cleaning of your ATV will not
only enhance its appearance but will improve its
general performance and extend the useful life of
many components.1. Before cleaning the ATV: a. Block off the end of the exhaust pipe toprevent water entry. A plastic bag and
strong rubber band may be used.
b. Make sure the spark plug and all filler caps are properly installed.
2. If the engine case is excessively greasy, apply degreaser with a paint brush. Do not apply
degreaser to the chain, sprockets or wheel
axles.
3. Rinse the dirt and degreaser off with a garden hose. Use only enough pressure to do the
job. WARNING! Wet brakes may have re-
duced stopping ability, increasing the
chance of an accident. Test the brakes af-
ter washing. Apply the brakes several
times at slow speeds to let friction dry out
the linings.
[EWB02312]
NOTICE: Excessive wa- ter pressure may cause water seepage
and deterioration of wheel bearings,
brakes, transmission seals and electrical
devices. Many expensive repair bills have
resulted from improper high-pressure de-
tergent applications such as those avail-
able in coin-operated car washers.
[ECB00712]
4. Once most of the dirt has been hosed off,
wash all surfaces with warm water and mild,
detergent-type soap. An old toothbrush or
bottle brush is handy for hard-to-reach pla-
ces.
5. Rinse the ATV off immediately with clean wa- ter and dry all surfaces with a chamois, clean
towel or soft absorbing cloth.
6. Dry the chain and lubricate it to prevent it from rusting.
7. Clean the seat with a vinyl upholstery cleaner to keep the cover pliable and glossy.
8. Automotive type wax may be applied to all painted and chrome plated surfaces. Avoid
combination cleaner-waxes. Many contain
UBW464E0.book Page 1 Thursday, January 23, 2020 2:42 PM

11-3
11
Transmission type:CVT automatic
Gear ratio: Transmission ratio:2.140–0.710 : 1
Forward gear: 10.967 (49/15 x 47/14)Front tire:Size:AT16x6.5-7
Manufacturer/model: DURO/DI2040Rear tire:Size:AT16x7-7
Manufacturer/model: DURO/DI2041Tire air pressure (measured on cold tires):Vehicle load:0.0–41.0 kg (0–90 lb)
Recommended: Front:15.0 kPa (0.150 kgf/cm², 2.2 psi)
Rear: 15.0 kPa (0.150 kgf/cm², 2.2 psi)
Minimum:
Front:12.0 kPa (0.120 kgf/cm², 1.7 psi)
Rear:
12.0 kPa (0.120 kgf/cm², 1.7 psi)
Front wheel:Rim size:7 x 5.2ATRear wheel:Rim size:7 x 5.2ATFront brake:Type:
Mechanical leading, trailing drum brakeRear brake:Type:Mechanical leading, trailing drum brakeFront suspension:Type:Swing axle
Spring: Coil spring
Shock absorber:
Gas-hydraulic damper
Wheel travel: 60 mm (2.4 in)Rear suspension:Type:
Swingarm
Spring: Coil spring
Shock absorber: Gas-hydraulic damper
Wheel travel:
51 mm (2.0 in)
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12-2
12
Part locations ................................................................. 4-1RRiding your ATV ............................................................. 8-1SSafety information .......................................................... 3-1
Seat .............................................................................. 5-13
Shock absorber, rear ...................................................5-13
Spark arrester, cleaning ............................................... 9-19
Spark plug, checking .....................................................9-9
Specifications ............................................................... 11-1
Speed limiter .................................................................. 5-3
Starter (choke) .............................................................. 5-12
Start switch .................................................................... 5-2
Steering shaft, lubricating ............................................ 9-32
Storage ......................................................................... 10-2TThrottle lever .......................................................... 5-3, 6-3
Throttle lever free play, adjusting ................................. 9-22
Tires ............................................................................... 6-3
Transmission oil ................................................... 6-3, 9-15
Troubleshooting ........................................................... 9-37
Troubleshooting chart .................................................. 9-38VValve clearance ............................................................ 9-22
Vehicle identification number ......................................... 1-1WWheel hub bearings, checking ..................................... 9-30
Wheel, installing ........................................................... 9-36
Wheel, removing .......................................................... 9-36YYamalube ..................................................................... 9-14UBW464E0.book Page 2 Thursday, January 23, 2020 2:42 PM