2020 YAMAHA YFZ50 carburetor

9-2
9
abrasives which may mar the paint or protec-
tive finish. When finished cleaning, start the
engine and let it idle for several minutes.
EBU30362StorageShort-term
Always store your ATV in a cool, dry place and, if
necessary, protect it against dust with a porous
cover.
NOTICE: Storing the ATV in a poorly ven-
tilated room or covering it with a tarp while it is
still wet, will allow water and humidity to seep
in and cause rust. To prevent corrosion, avoid
damp cellars, stables (because of the presence
of ammonia) and areas where strong chemi-
cals are stored.
[ECB00722]
Long-term
Before storing your ATV for several months: 1. Make any necessary repairs and perform all outstanding maintenance.
2. Follow all the instructions in the Cleaning sec- tion of this chapter. 3. Fill up the fuel tank and add fuel stabilizer (Fu-
el Med Rx if available), and then run the en-
gine for 5 minutes to distribute the treated
fuel.
4. Turn the fuel cock lever off, and then drain the carburetor float chamber by loosening the
drain bolt. Pour the drained fuel into the fuel
tank.
5. Perform the following steps to protect the en- gine from internal corrosion.a. Remove the spark plug cap and spark plug.
b. Pour a teaspoonful of engine oil into the spark plug bore.
c. Install the spark plug cap onto the spark plug, and then place the spark plug on the
cylinder head so that the electrodes are
grounded. (This will limit sparking during
the next step.)
d. Turn the engine over several times with the starter. (This will coat the cylinder wall
with oil.)
Specified amount:
7.5 ml per liter of fuel (1 oz per gallon)UBW463E0.book Page 2 Monday, January 28, 2019 10:22 AM

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Engine oil:Recommended brand:
SAE viscosity grades:5W-30, 10W-30, 10W-40, 15W-40, 20W-40, 20W-50
Recommended engine oil grade: API service SG type or higher, JASO standard MA
Quantity: Oil change: 0.80 L (0.85 US qt, 0.70 Imp.qt)Transmission oil:Type:SAE 80W-90
Quantity: 0.35 L (0.37 US qt, 0.31 Imp.qt)
Air filter:Air filter element:Wet element
Air filter oil grade:
Foam air-filter oilFuel:Recommended fuel:Regular unleaded gasoline only
Minimum research octane:
91
Fuel tank capacity: 5.6 L (1.5 US gal, 1.2 Imp.gal)
Fuel reserve amount: 0.7 L (0.18 US gal, 0.15 Imp.gal)Carburetor:Type × quantity:
VM12 × 1Spark plug (s):Manufacturer/model:
NGK/CR6HSA
Spark plug gap: 0.6–0.7 mm (0.024–0.028 in)Drivetrain:Primary reduction ratio:
1.000
Secondary reduction ratio: 2.923 (38/13)
Final drive: Chain
Clutch type:
Dry, centrifugal, shoe
0 10 30 50 70 90 110 130 ˚F
–20 –10 0 10 20 30 40 50 ˚CSAE 5W-30
SAE 10W-30
SAE 10W-40
SAE 15W-40
SAE 20W-40SAE 20W-50
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INDEX
AAccessories and loading ................................................ 6-5
Air filter element, cleaning ........................................... 8-16BBattery ......................................................................... 8-32
Brake lever free play, adjusting the front ..................... 8-24
Brake lever free play (rear), adjusting .......................... 8-26
Brake lever, front ........................................................... 4-5
Brake lever, rear ............................................................. 4-6
Brake levers, checking and lubricating ........................ 8-30
Brakes .......................................................................... 8-22
Brakes, front and rear .................................................... 5-3CCables, checking and lubricating ................................ 8-29
Carburetor, adjusting ................................................... 8-20
Chassis fasteners .......................................................... 5-6
Cleaning ......................................................................... 9-1DDrive chain ..................................................................... 5-3
Drive chain, cleaning and lubricating ........................... 8-29
Drive chain slack .......................................................... 8-26EEngine break-in .............................................................. 6-3
Engine, cold start ........................................................... 6-1
Engine idling speed ..................................................... 8-20
Engine oil ..............................................................5-3, 8-11
Engine, starting a warm ................................................. 6-3
Engine stop switch ........................................................ 4-1
Engine stop switch with lanyard .................................... 4-2
FFront and rear brake shoes, checking ......................... 8-23
Front arm pivots, lubricating ........................................ 8-31
Front knuckle pivots, lubricating ................................. 8-31
Fuel ......................................................................... 4-9, 5-3
Fuel cock ..................................................................... 4-10
Fuel tank cap ................................................................. 4-8
Fuse, replacing ............................................................ 8-35HHandlebar switches ....................................................... 4-1IIdentification numbers ................................................. 11-1
Instruments and switches .............................................. 5-6KKickstarter ...................................................................... 4-7LLabel locations ............................................................... 1-1MMain switch .................................................................... 4-1
Maintenance and lubrication chart ................................ 8-5
Maintenance chart, emission control system ................ 8-3
Model label .................................................................. 11-1OOwner’s Manual and tool kit .......................................... 8-2PPanel, removing and installing ....................................... 8-9
Parking ........................................................................... 6-3
Parking brake ................................................................. 4-6
Parking on a slope ......................................................... 6-4
UBW463E0.book Page 1 Monday, January 28, 2019 10:22 AM