Page 15 of 426

OPERATION ...........................................6-1
Starting a cold engine ..........................6-3
Starting a warm engine ........................6-9
Warming up ..........................................6-9
Reverse knob operation and
reverse driving ..................................6-11
Shifting ................................................6-15
To start out and accelerate .................6-17
To decelerate ......................................6-21
Engine break-in ..................................6-23
Parking ...............................................6-27
Parking on a slope ..............................6-29
Accessories and loading ....................6-31
RIDING YOUR ATV..................................7-1
Getting to know your ATV .....................7-3
Ride with care and good judgement .....7-5
Be careful where you ride ...................7-27
Turning your ATV ................................7-39
Climbing uphill.....................................7-45
Riding downhill ....................................7-55
Crossing a slope .................................7-59
Crossing through shallow water ..........7-63
Riding over rough terrain ....................7-67
Sliding and skidding ............................7-69
What to do if .......................................7-73
What to do...........................................7-73
67
PERIODIC MAINTENANCE AND
ADJUSTMENT ........................................ 8-1
Owner’s manual and tool kit ................. 8-3
Periodic maintenance/lubrication ......... 8-7
Panel removal and installation ........... 8-15
Engine oil and oil filter cartridge ......... 8-17
Cooling system ................................... 8-33
Changing the coolant.......................... 8-37
Spark plug inspection ......................... 8-45
Air filter element cleaning ................... 8-49
Carburetor adjustment ....................... 8-55
Idle speed adjustment ........................ 8-57
Throttle lever adjustment ................... 8-59
Valve clearance adjustment .............. 8-61
Front and rear brake pad inspection... 8-63
Brake fluid level inspection ................. 8-65
Brake fluid replacement ...................... 8-69
Front brake lever free play.................. 8-71
Brake pedal height adjustment ........... 8-73
Parking brake adjustment ................... 8-75
Adjusting the rear brake light switch ... 8-79
Clutch lever free play adjustment ...... 8-81
Drive chain slack check ...................... 8-83
Drive chain slack adjustment .............. 8-85
Lubricating the drive chain ................. 8-87
Cable inspection and lubrication ........ 8-91
8
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Page 122 of 426
5-5
EBU01167
Front and rear brakes
Brake lever and brake pedal
Check that there is no free play in the brake le-
ver. If there is free play, have a Yamaha dealer
inspect the brake system.
Check for correct brake pedal height. (See
page 8-73.) If the pedal height is incorrect,
have a Yamaha dealer adjust it.
Check the operation of the brake lever and
brake pedal. They should move smoothly and
there should be a firm feeling when the brakes
are applied. If not, have a Yamaha dealer in-
spect the brake system.
Brake fluid level
Check the brake fluid level. Add fluid if necessary.
(See pages 8-65–8-69.)
Recommended brake fluid: DOT 4
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Page 336 of 426
8-73 a. Brake pedal position
a. Position de la pédale de frein
a. Posición del pedal del freno
EBU01079
Brake pedal height adjustment
The top of the brake pedal should be positioned
4 mm below the top of the footrest. If not, have a
Yamaha dealer adjust it.
WARNING
_ Operating with improperly serviced or adjust-
ed brakes could cause loss of braking ability,
which could lead to an accident. After servic-
ing:
Make sure the brakes operate smoothly
and that the brake pedal position is cor-
rect.
Make sure the brakes do not drag.
Make sure the brakes are not spongy. All
air must be bled from the brake system.
Replacement of brake components requires
professional knowledge. These procedures
should be performed by a Yamaha dealer.
_
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10-1
EBU00428
SPECIFICATIONS
MODEL YFM660R
Dimension:
Overall length
Overall width
Overall height
Seat height
Wheel base
Ground clearance
Minimum turning radius1,830 mm
1,100 mm
1,150 mm
860 mm
1,245 mm
265 mm
3,300 mm
Basic weight:
With oil and full fuel tank 193 kg
Engine:
Type
Cylinder arrangement
Displacement
Bore
× stroke
Compression ratio
Starting system
Lubrication systemLiquid-cooled, 4-stroke, SOHC
Forward inclined single cylinder
660 cm
3
100
× 84 mm
9.2 : 1
Electric starter
Dry sump
U5LP63.book Page 1 Monday, March 10, 2003 2:06 PM