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8
8. Check the differential gear case for oil leak-
age. If oil is leaking, check for the cause.
EBU23472CoolantThe coolant level should be checked regularly. In
addition, the coolant must be changed at the in-
tervals specified in the periodic maintenance and
lubrication chart.
TIPIf genuine Yamaha coolant is not available, use an
ethylene glycol antifreeze containing corrosion in-
hibitors for aluminum engines and mix with dis-
tilled water at a 1:1 ratio. NOTICEECB02190Mix antifreeze with distilled water only. Howev-
er, if distilled water is not available, soft water
may be used for refilling. Do not use hard water
or salt water since they are harmful to the en-
gine. EBU2712ATo check the coolant level1. Park the ATV on a level surface.TIPThe coolant level must be checked on a cold en-
gine since the level varies with engine tempera-
ture. 2. Check the coolant level in the coolant reser- voir.
Tightening torque:
Differential gear oil filler bolt:23 N·m (2.3 kgf·m, 17 lb·ft)
Recommended coolant: YAMALUBE coolant
Coolant quantity: Coolant reservoir (up to full level):0.25 L (0.26 US qt, 0.22 Imp.qt)
Radiator (including all routes): 1.32 L (1.40 US qt, 1.16 Imp.qt)
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Be careful that water does not enter the
brake fluid reservoir when refilling. Water will
significantly lower the boiling point of the flu-
id and may result in vapor lock.
EBU24283Changing the brake fluidHave a Yamaha dealer change the brake fluid at
the intervals specified in the periodic maintenance
and lubrication chart. In addition, have the oil seals
of the brake master cylinder and calipers as well
as the brake hoses replaced at the intervals listed
below or whenever they are damaged or leaking.
Oil seals: Replace every two years.
Brake hoses: Replace every four years.
EBU24396Checking the front brake lever free
playThere should be no free play at the brake lever
end. If there is free play, have a Yamaha dealer in-
spect the brake system.EBU30348Adjusting the rear brake lever and
brake pedalThe rear brake lever free play, brake pedal free
play, and the brake pedal height must be checked
and adjusted at the intervals specified in the peri-
odic maintenance chart.1. No brake lever free play
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Carbon dioxide (CO2) level:Carbon dioxide (CO2) emissions (2016/1628):1015.0 g/kWh (YFM450FWB, YFM450FWBD)Engine:Combustion cycle:4-stroke
Cooling system: Liquid cooled
Valve train:
SOHC
Number of cylinders: Single cylinder
Displacement: 421 cm³
Bore × stroke:
84.5 × 75.0 mm (3.33 × 2.95 in)
Compression ratio: 10.0 : 1
Starting system: Electric starter
Lubrication system:
Wet sumpEngine 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: 2.30 L (2.43 US qt, 2.02 Imp.qt)
With oil filter removal: 2.40 L (2.54 US qt, 2.11 Imp.qt)
Final gear oil:Type:Yamaha Friction Modified Shaft Drive Gear Oil
Quantity: 0.38 L (0.40 US qt, 0.33 Imp.qt)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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