2021 YAMAHA YFM90R engine oil

9-12
9
2. Start the engine, warm it up for several minu-
tes, and then turn it off.
3. Place an oil pan under the engine to collect the used oil.
4. Remove the engine oil filler cap, and then re- move the engine oil drain bolt to drain the oil
from the crankcase. NOTICE: When remov-
ing the engine oil drain bolt, the compres-
sion spring, oil strainer and O-ring will fall
out. Take care not to lose these parts.
[ECB00312]
5. Clean the oil strainer with solvent.
6. Discard the old engine oil drain bolt O-ring, and then apply a thin coat of clean engine oil
to the new O-ring.
7. Install the oil strainer, the compression spring, the new O-ring and the engine oil
drain bolt. Tighten the engine oil drain bolt to
the specified torque. NOTICE: Before in-
stalling the engine oil drain bolt, be sure to
install the O-ring, compression spring and
oil strainer.
[ECB00322]
8. Refill with the specified amount of the recom- mended engine oil.
1. Engine oil drain bolt
2. O-ring
3. Compression spring
4. Oil strainer
4321
Tightening torque:Engine oil drain bolt:15 N

9-13
9
TIPBe sure to wipe off spilled oil on any parts after the
engine and exhaust system have cooled down. NOTICEECB00331Do not use oils with a diesel specification of
“CD” or oils of a higher quality than speci-
fied. In addition, do not use oils labeled “EN-
ERGY CONSERVING II” or higher.
 Make sure that no foreign material enters the
crankcase. 9. Check the engine oil filler cap O-ring for dam-
age, and then install and tighten the engine oil
filler cap.
10. Start the engine, and then let it idle for several minutes while checking it for oil leakage. If oil
is leaking, immediately turn the engine off and
check for the cause.
11. Turn the engine off, wait at least ten minutes, and then check the oil level and correct it if
necessary.
EBU38620Why YamalubeYAMALUBE oil is a Genuine YAMAHA Part born ofthe engineers’ passion and belief that engine oil is
an important liquid engine component. We form
teams of specialists in the fields of mechanical en-
gineering, chemistry, electronics and track test-
ing, and have them develop the engine together
with the oil it will use. Yamalube oils take full ad-
vantage of the base oil’s qualities and blend in the
ideal balance of additives to make sure the final oil
clears our performance standards. Thus,
Yamalube mineral, semi synthetic and synthetic
oils have their own distinct characters and value.
Yamaha’s experience gained over many years of research and development into oil since the
1960’s helps make Yamalube the best choice for
your Yamaha engine.
UBD365E0.book Page 13 Monday, January 27, 2020 9:05 AM

9-17
95. Squeeze the excess solvent out of the air filter
element and let it dry. NOTICE: Do not twist
the air filter element when squeezing it.
[ECB02310]
6. Check the air filter element and replace it if damaged.
7. Apply Yamaha foam air filter oil or other qual- ity foam air filter oil to the element.TIPThe air filter element should be wet but not drip-
ping. 8. Insert the air filter element into the air filtercase.
9. Install the air filter case cover by hooking the holders onto the air filter case. NOTICE:
Make sure that the air filter element is
properly seated in the air filter case. Never
operate the engine with the air filter ele-
1. Air filter element
1
UBD365E0.book Page 17 Monday, January 27, 2020 9:05 AM

9-28
9
1. Clean the drive chain with kerosene and a
small soft brush. NOTICE: To prevent dam-
aging the O-rings, do not clean the drive
chain with steam cleaners, high-pressure
washers or inappropriate solvents.
[ECB00572]
2. Wipe the drive chain dry.
3. Thoroughly lubricate the drive chain with a special O-ring chain lubricant. NOTICE: Do
not use engine oil or any other lubricants
for the drive chain, as they may contain
substances that could damage the O-
rings.
[ECB00582]
EBU24905
Checking and lubricating the cablesThe operation and the condition of all control ca-
bles should be checked before each ride, and the
cables and cable ends should be lubricated if nec-
essary. If a cable is damaged or does not move
smoothly, have a Yamaha dealer check or replace
it.
WARNING
EWB02582 Inspect cables frequently and replace if
damaged. Corrosion can result when the ca-
ble sheaths become damaged, and cables
can also become frayed or kinked, which
could restrict the operation of controls and
lead to an accident or injury.
 Always make sure all control cables work
smoothly before you begin riding in cold
weather. If the control cables are frozen or
do not work smoothly, you could be unable
to control the ATV, which could lead to an
accident or collision. EBU28703Checking and lubricating the front and
rear brake leversThe operation of the front and rear brake levers
should be checked before each ride, and the lever
pivots should be lubricated if necessary.
Recommended lubricant: Yamaha cable lubricant or other suitable cable lubricantRecommended lubricant: Lithium-soap-based grease
UBD365E0.book Page 28 Monday, January 27, 2020 9:05 AM

10-2
10abrasives 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)UBD365E0.book Page 2 Monday, January 27, 2020 9:05 AM

11-2
11
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 (Gasohol [E10] acceptable)
Minimum research octane:
91
Fuel tank capacity: 6.6 L (1.7 US gal, 1.5 Imp.gal)
Fuel reserve amount: 0.9 L (0.24 US gal, 0.20 Imp.gal)Carburetor:Type × quantity:
H66D16 × 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: 2.500 (35/14)
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
UBD365E0.book Page 2 Monday, January 27, 2020 9:05 AM

12-1
12
INDEX
AAccessories and loading ................................................ 7-6
Air filter element, cleaning ............................................ 9-15BBattery .......................................................................... 9-31
Brake lever free play, adjusting the front ..................... 9-23
Brake lever free play (rear), adjusting ........................... 9-24
Brake lever, front ............................................................ 5-5
Brake lever, rear ............................................................. 5-5
Brake levers, checking and lubricating ........................ 9-28
Brakes .......................................................................... 9-21
Brakes, front and rear .................................................... 6-3CCables, checking and lubricating ................................. 9-28
Carburetor, adjusting ...................................................9-19
Chassis fasteners ........................................................... 6-6
Cleaning ....................................................................... 10-1DDrive chain ..................................................................... 6-3
Drive chain, lubricating ................................................ 9-27
Drive chain slack .......................................................... 9-25
Drive select lever ............................................................ 5-6
Drive select lever and driving in reverse ........................ 7-3EEngine break-in .............................................................. 7-4
Engine, cold start ........................................................... 7-1
Engine idling speed ...................................................... 9-19
Engine oil .............................................................. 6-3, 9-10
Engine, starting a warm ................................................. 7-3Engine stop switch ......................................................... 5-2
FFront and rear brake shoes, checking ......................... 9-21
Front arm pivots, lubricating ........................................ 9-29
Front knuckle pivots, lubricating .................................. 9-30
Fuel ........................................................................ 5-9, 6-3
Fuel cock ...................................................................... 5-10
Fuel tank cap ................................................................. 5-8
Fuse, replacing ............................................................. 9-34HHandlebar switches ....................................................... 5-2IIdentification numbers ................................................... 1-1
Indicator lights ............................................................... 5-1
Instruments and switches .............................................. 6-6KKickstarter ...................................................................... 5-7LLabel locations ............................................................... 2-1MMain switch .................................................................... 5-1
Maintenance and lubrication chart ................................ 9-5
Maintenance chart, emission control system ................ 9-3
Model label .................................................................... 1-1NNeutral indicator light ..................................................... 5-1OOwner’s Manual and tool kit .......................................... 9-2
UBD365E0.book Page 1 Monday, January 27, 2020 9:05 AM