2018 YAMAHA YFZ450R engine

8-52
8Engine overheating
WARNING
EWB02291Wait for the engine and radiator to cool before removing the radiator cap. You could be burned by
hot fluid and steam blown out under pressure. Always put a thick rag over the cap when opening.
Allow any remaining pressure to escape before completely removing the cap. TIPIf coolant is not available, tap water can be temporarily used instead, provided that it is changed to the
recommended coolant as soon as possible. Wait until the
engine has cooled.
Check the coolant level in the
reservoir and radiator.
The coolant level
is OK.The coolant level is low.
Check the cooling system
for leakage.
Have a Yamaha dealer check
and repair the cooling system.Add coolant. (See TIP.)
Start the engine. If the engine overheats again, have a
Yamaha dealer check and repair the cooling system.
There is
leakage.
There is
no leakage.
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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
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9-2
9abrasives which may mar the paint or protec-
tive finish. When finished cleaning, start the
engine and let it idle for several minutes.
EBU27264StorageShort-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. 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.)
e. Remove the spark plug cap from the spark plug, and then install the spark plug and
the spark plug cap.
5. Lubricate all control cables and the pivoting points of all levers and pedals.
Specified amount:
7.5 ml per liter of fuel (1 oz per gallon)UBW261E0.book Page 2 Friday, May 26, 2017 9:38 AM

10-1
10
EBU25962
SPECIFICATIONS
Dimensions:Overall length:1795 mm (70.7 in)
Overall width: 1240 mm (48.8 in)
Overall height:
1065 mm (41.9 in)
Seat height: 810 mm (31.9 in)
Wheelbase: 1270 mm (50.0 in)
Ground clearance:
235 mm (9.3 in)
Minimum turning radius: 3600 mm (142 in)Weight:Curb weight:
184.0 kg (406 lb)Noise and vibration level:Noise level (77/311/EEC):85.9 dB(A) at 3750 r/min
Uncertainty of measurement:
3.0 dB(A)
A-weighted sound power level: 99.0 dB(A) at 3750 r/min
Uncertainty of measurement: 3.0 dB(A) Vibration on seat (EN1032, ISO5008):
Will not exceed 0.5 m/s²
Uncertainty of measurement: 0.1 m/s²
Vibration on handle (EN1032, ISO5008): Will not exceed 2.5 m/s²
Uncertainty of measurement:
0.8 m/s²
Engine:Engine type:Liquid cooled 4-stroke, DOHC
Cylinder arrangement:
Single cylinder
Displacement: 449 cm³
Bore × stroke:
95.0 × 63.4 mm (3.74 × 2.50 in)
Compression ratio:
11.8 : 1
Starting system: Electric starter
Lubrication system: Dry sumpEngine oil:Recommended brand:YAMALUBE
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10-2
10
Type:SAE 5W-30, 10W-30, 10W-40, 15W-40, 20W-40 or 20W-
50
Recommended engine oil grade: API service SG type or higher, JASO standard MA
Engine oil quantity: Without oil filter element replacement:1.40 L (1.48 US qt, 1.23 Imp.qt)
With oil filter element replacement: 1.45 L (1.53 US qt, 1.28 Imp.qt)Coolant quantity:Coolant reservoir (up to the maximum level mark):0.25 L (0.26 US qt, 0.22 Imp.qt)
Radiator (including all routes): 1.25 L (1.32 US qt, 1.10 Imp.qt)Air filter:Air filter element:Wet element
Fuel:Recommended fuel:Premium unleaded gasoline only
Fuel tank capacity:
10.0 L (2.64 US gal, 2.20 Imp.gal)
Fuel reserve amount: 3.4 L (0.90 US gal, 0.75 Imp.gal)Fuel injection:Throttle body:
ID mark:1TD1 00Spark plug (s):Manufacturer/model:NGK/CR8E
Spark plug gap: 0.7–0.8 mm (0.028–0.031 in)Clutch:Clutch type:Wet, multiple-discTransmission:Primary reduction ratio:
61/23 (2.652)
Secondary reduction system: Chain drive
Secondary reduction ratio: 38/14 (2.714)
Transmission type:
Constant mesh 5-speed
Operation: Left foot operation
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
UBW261E0.book Page 2 Friday, May 26, 2017 9:38 AM

10-4
10
Specified brake fluid:DOT 4Rear brake:Type:
Hydraulic disc brake
Operation: Right foot operation
Specified brake fluid: DOT 4Front suspension:Type:Double wishbone
Spring/shock absorber type: Coil spring/gas-oil damper
Wheel travel:
250 mm (9.9 in)Rear suspension:Type:Swingarm (link suspension)
Spring/shock absorber type:
Coil spring/gas-oil damper
Wheel travel: 280 mm (11.0 in)Electrical system:Ignition system:
TCI
Charging system: AC magnetoBattery:Model:
YTZ7S Voltage, capacity:
12 V, 6.0 Ah
Headlight(s):Bulb type:
Krypton bulbBulb voltage, wattage × quantity:Headlight:
12 V, 30.0/30.0 W × 2
Tail/brake light:
LED
Neutral indicator light: LED
Fuel level warning light: LED
Coolant temperature warning light:
LED
Engine trouble warning light: LEDFuse:Fuse:
20.0 AEBU30403Noise and vibration levels statement (for Eu-
rope)
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
UBW261E0.book Page 4 Friday, May 26, 2017 9:38 AM

12-1
12
INDEX
AAccessories and loading ................................................ 6-5
Air filter element, cleaning ........................................... 8-21BBattery ......................................................................... 8-42
Brake and clutch levers, checking and lubricating ...... 8-39
Brake fluid, changing ................................................... 8-31
Brake fluid level, checking ........................................... 8-29
Brake lever ..................................................................... 4-5
Brake lever free play, checking the front ..................... 8-31
Brake light switches ..................................................... 8-34
Brake pads, checking the front and rear ..................... 8-28
Brake pedal .................................................................... 4-6
Brake pedal, checking and lubricating ........................ 8-39
Brake pedal height, checking ...................................... 8-32
Brakes .......................................................................... 8-28
Brakes, front and rear .................................................... 5-4CCables, checking and lubricating ................................ 8-38
Chassis fasteners .......................................................... 5-7
Cleaning ......................................................................... 9-1
Clutch lever .................................................................... 4-5
Clutch lever free play, adjusting .................................. 8-34
Coolant .................................................................5-4, 8-20
Coolant temperature warning light ................................ 4-2
Cowling and panels, removing and installing .............. 8-10DDrive chain ..................................................................... 5-5
Drive chain, lubricating ................................................ 8-37 Drive chain slack .......................................................... 8-35
EEngine break-in .............................................................. 6-4
Engine oil ....................................................................... 5-4
Engine oil and oil filter element .................................... 8-14
Engine, start ................................................................... 6-1
Engine stop switch ........................................................ 4-3
Engine trouble warning light .......................................... 4-2FFuel ......................................................................... 4-8, 5-4
Fuel level warning light .................................................. 4-2
Fuel tank cap ................................................................. 4-8
Fuse, replacing ............................................................ 8-45HHandlebar position, adjusting ...................................... 4-23
Handlebar switches ....................................................... 4-3
Headlight beam, adjusting ........................................... 8-48
Headlight bulb, replacing ............................................. 8-46IIdentification numbers ................................................. 11-1
Indicator light and warning lights ................................... 4-1
Instruments, lights and switches ................................... 5-7LLabel locations ............................................................... 1-1
Light switch ................................................................... 4-3MMain switch .................................................................... 4-1
Maintenance and lubrication chart ................................ 8-5
Maintenance chart, emission control system ................ 8-3
UBW261E0.book Page 1 Friday, May 26, 2017 9:38 AM