2018 YAMAHA YFZ50 Clearance

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 for the emission control system ........................... 8-3
General maintenance and lubrication chart .......................................................... 8-5
Removing and installing the panel .............. 8-9
Checking the spark plug ............................. 8-9
Engine oil................................................... 8-11
Transmission oil ........................................ 8-14 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 ......... 8-21
Valve clearance......................................... 8-22
Brakes....................................................... 8-22
Checking the front and rear brake
shoes ...................................................... 8-22
Adjusting the front brake lever free play... 8-23
Adjusting the rear brake lever free play .... 8-25
Drive chain slack....................................... 8-26
Cleaning and lubricating the drive chain ....................................................... 8-28
Checking and lubricating the cables ........ 8-29
Checking and lubricating the front and rear brake levers ..................................... 8-29
Checking the wheel hub bearings ............ 8-30
Lubricating the front arm pivots ............... 8-30
Lubricating the front knuckle pivots ......... 8-31
Lubricating the steering shaft ................... 8-31
Battery ...................................................... 8-32
Replacing the fuse .................................... 8-35
Removing a wheel .................................... 8-35
Installing a wheel ...................................... 8-36
Troubleshooting........................................ 8-37
Troubleshooting chart .............................. 8-38UBW461E0.book Page 2 Tuesda y, January 31, 2017 5:13 PM

2-5
2
4. Once immediate safety hazards are con-
firmed not to exist, you may remove your hel-
met to more closely inspect your vehicle.
Check for external signs of wear, broken
parts, fluid leaks, cracks in the frame, sus-
pension damage, wheel damage, and so on.
Fuel, oil, and coolant usually give off a notice-
able odor.
5. If your vehicle will not restart or if it is unsafe to ride, then turn off all vehicle systems (en-
gine stop switch, main switch, and fuel cock),
and then signal or go for help.
Aftermarket Parts, Accessories, and Modifica-
tions
While you may find aftermarket products similar in
design and quality to genuine Yamaha accesso-
ries, recognize that some aftermarket accessories
or modifications are not suitable because of po-
tential safety hazards to you or others. Installing
aftermarket products or having other modifica-
tions performed to your vehicle that change any of
the vehicle’s design or operation characteristics
can put you and others at greater risk of serious
injury or death. You are responsible for injuries re-
lated to changes in the vehicle. Keep the following
guidelines in mind, as well as those found in the Loading section (page 6-6) when mounting acces-
sories.

Never install accessories that would impair the
performance of your ATV. Carefully inspect the
accessory before using it to make sure that it
does not in any way reduce ground clearance,
limit suspension travel, steering travel or control
operation.
 Accessories fitted to the ATV can create insta-
bility due to improper weight distribution.
 Bulky or large accessories may seriously affect
the stability of the ATV.
 Certain accessories can displace the operator
from his or her normal riding position. This im-
proper position limits the freedom of movement
of the operator and may limit control ability,
therefore, such accessories are not recom-
mended.
 Use caution when adding electrical accesso-
ries. If electrical accessories exceed the capac-
ity of the ATV’s electrical system, an electric
failure could result, which could cause a dan-
gerous loss of lights or engine power. Also, the
battery tends to discharge more quickly if elec-
trical accessories are added.
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8-3
8
EBU36870Periodic maintenance chart for the emission control systemTIPFor ATVs not equipped with an odometer or an hour meter, follow the month maintenance intervals.
 For ATVs equipped with an odometer or an hour meter, follow the km (mi) or hours maintenance inter-
vals. However, keep in mind that if the ATV isn’t used for a long period of time, the month maintenance
intervals should still be followed.
 Items marked with an asterisk should be performed by a Yamaha dealer as they require special tools,
data and technical skills. 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
1 *Fuel line • Check fuel hoses for cracks or other damage, and
replace if necessary. √√√
2Spark plug • Check condition and clean, regap, or replace if
necessary. √√√√√
3 *Va l v e s • Check valve clearance and adjust if necessary. √ √√√
4 *Carburetor • Check starter (choke) operation and correct if
necessary.
• Check engine idling speed and adjust if neces- sary. √ √√√
5 *Crankcase breath-
er system • Check breather hose for cracks or other damage,
and replace if necessary. √√√
UBW461E0.book Page 3 Tuesda
y, January 31, 2017 5:13 PM

8-22
84. Tighten the locknut.
5. Slide the rubber covers to their original posi-
tions.
EBU24061Valve clearanceThe valve clearance changes with use, resulting in
improper air-fuel mixture and/or engine noise. To
prevent this from occurring, the valve clearance
must be adjusted by a Yamaha dealer at the inter-
vals specified in the periodic maintenance and lu-
brication chart.
EBU29602BrakesReplacement of brake components requires pro-
fessional knowledge. Brake service should be
performed by a Yamaha dealer.
WARNING
EWB02572Operating with improperly serviced or adjust-
ed brakes could lead to a loss in braking ability
and an accident. EBU34511Checking the front and rear brake
shoesThe front and rear brake shoes must be checked
for wear at the intervals specified in the periodic
maintenance and lubrication chart. Without disas-
sembling the brake, this can be performed by
checking the position of the brake lever free play
adjusting bolts or nut.
Front brakes
To check front brake shoe wear, check the posi-
tion of the adjusting bolts. If a bolt extends more
than 12 mm (0.47 in) from its locknut, the brake
shoes need to be replaced.
1. Rubber cover
2. Throttle lever free play adjusting nut
3. Locknut
4. Throttle lever free play
1
2
3
1
4
(a)(b)
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EBU25962
SPECIFICATIONS
Dimensions:Overall length:1250 mm (49.2 in)
Overall width: 820 mm (32.3 in)
Overall height:
770 mm (30.3 in)
Seat height: 585 mm (23.0 in)
Wheelbase: 830 mm (32.7 in)
Ground clearance:
88 mm (3.5 in)
Minimum turning radius: 2300 mm (91 in)Weight:Curb weight:
100.0 kg (220 lb)Noise and vibration level:Noise level (77/311/EEC):74.0 dB(A) (EUR, FRA, GBR)
Uncertainty of measurement:
2.0 dB(A) (EUR, FRA, GBR)
Vibration on seat (EN1032, ISO5008): Will not exceed 0.5 m/s² (EUR, FRA, GBR)
Uncertainty of measurement: 0.1 m/s² (EUR, FRA, GBR) Vibration on handle (EN1032, ISO5008):
4.7 m/s² (EUR, FRA, GBR)
Uncertainty of measurement: 0.4 m/s² (EUR, FRA, GBR)
Engine:Engine type:
Air cooled 4-stroke, SOHC
Cylinder arrangement: Single cylinder
Displacement: 49 cm³
Bore × stroke:
39.0 × 41.4 mm (1.54 × 1.63 in)
Compression ratio: 8.5 : 1
Starting system: Electric starter and kickstarter
Lubrication system:
Wet sumpEngine oil:Recommended brand:YAMALUBE
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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