2018 YAMAHA YFZ50 ABS

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 ............................................................. 4-8
Fuel cock................................................... 4-10 Starter (choke) ......................................... 4-11
Seat .......................................................... 4-12
Adjusting the 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 ............................ 6-5UBW461E0.book Page 1 Tuesda y, January 31, 2017 5:13 PM

3-1
3
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 spring preload adjuster
6. Kickstarter lever cap
7. Throttle stop screw
12
4
5
3
6
7
1. Spark arrester
2. Owner’s tool kit
3. Fuse
4. Battery
5. Spark plug
6. Engine oil filler cap
7. Transmission oil filler cap
12
3,4
5
67
UBW461E0.book Page 1 Tuesda y, January 31, 2017 5:13 PM

4-13
4
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.
EBU19025Adjusting the rear shock absorberThe spring preload can be adjusted to suit the rid-
er’s weight and the riding conditions.
NOTICEECB01091Never turn the adjusting mechanism beyond
the minimum and maximum settings. Adjust the spring preload as follows.
Turn the spring preload adjusting ring in direction
(a) to increase the spring preload and thereby
harden the suspension, and in direction (b) to de-
crease the spring preload and thereby soften the
suspension.
1. Projection
2. Seat holder
2
1
1. Spring preload adjusting ring
2. Position indicator
1
234 52
1
(a)
(b)
UBW461E0.book Page 13 Tuesday, January 31, 2017 5:13 PM

8-6
8
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. √√√
9Drive 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 320UBW461E0.book Page 6 Tuesda y, January 31, 2017 5:13 PM

9-1
9
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
UBW461E0.book Page 1 Tuesda y, January 31, 2017 5:13 PM

10-3
10
Caster angle:1.10 °
Trail: 10.4 mm (0.41 in)Front tire:Type:Tubeless
Size: AT16 x 6.5-7
Manufacturer/model:
DURO/DI2040Rear tire:Type:Tubeless
Size:
AT16 x 7-7
Manufacturer/model: DURO/DI2041Loading:Maximum loading limit:
41.0 kg (90 lb)
(Total weight of rider, cargo, accessories, and tongue)Tire air pressure (measured on cold tires):Recommended:Front:
13.8 kPa (0.138 kgf/cm², 2.0 psi)
Rear: 13.8 kPa (0.138 kgf/cm², 2.0 psi)
Minimum: Front: 12.4 kPa (0.124 kgf/cm², 1.8 psi) Rear:
12.4 kPa (0.124 kgf/cm², 1.8 psi)
Front wheel:Wheel type:
Panel wheel
Rim size: 7 x 5.2ATRear wheel:Wheel type:
Panel wheel
Rim size: 7 x 5.2ATFront brake:Type:
Mechanical leading, trailing drum brake
Operation: Right hand operationRear brake:Type:
Mechanical leading, trailing drum brake
Operation: Left hand operationFront suspension:Type:
Swing axle
Spring/shock absorber type: Coil spring/oil damper
Wheel travel: 60 mm (2.4 in)
UBW461E0.book Page 3 Tuesda y, January 31, 2017 5:13 PM

10-4
10
Rear suspension:Type:Swingarm
Spring/shock absorber type:
Coil spring/oil damper
Wheel travel: 51 mm (2.0 in)Electrical system:Ignition system:
CDI
Charging system: AC magnetoBattery:Model:
GTX5L-BS
Voltage, capacity: 12 V, 4.0 AhFuse:Fuse:
7.5 AEBU30402For Europe only
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.UBW461E0.book Page 4 Tuesda
y, January 31, 2017 5:13 PM

12-2
12
Part locations ................................................................. 3-1RRiding your ATV ............................................................. 7-1SSafety information .......................................................... 2-1
Seat .............................................................................. 4-12
Shock absorber, adjusting the rear ............................. 4-13
Spark arrester, cleaning ............................................... 8-19
Spark plug, checking ..................................................... 8-9
Specifications .............................................................. 10-1
Speed limiter .................................................................. 4-3
Starter (choke) ............................................................. 4-11
Start switch .................................................................... 4-2
Steering shaft, lubricating ............................................ 8-31
Storage .......................................................................... 9-2TThrottle lever ...........................................................4-3, 5-3
Throttle lever free play, adjusting ................................ 8-21
Tires ............................................................................... 5-3
Transmission oil ....................................................5-3, 8-14
Troubleshooting ........................................................... 8-37
Troubleshooting chart .................................................. 8-38VValve clearance ............................................................ 8-22
Vehicle identification number ...................................... 11-1WWheel hub bearings, checking .................................... 8-30
Wheel, installing ........................................................... 8-36
Wheel, removing .......................................................... 8-35
UBW461E0.book Page 2 Tuesday, January 31, 2017 5:13 PM