Page 17 of 376

OPERATION ............................................6-1
Starting a cold engine ...........................6-3
Starting a warm engine ........................6-9
Warming up ..........................................6-9
Drive select lever operation and
reverse driving .................................6-11
Shifting ................................................6-15
To start out and accelerate .................6-17
To decelerate ......................................6-19
Engine break-in ...................................6-21
Parking ...............................................6-23
Parking on a slope .............................6-25
Accessories and loading ....................6-27
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 ................................7-41
Climbing uphill.....................................7-47
Riding downhill ....................................7-57
Crossing a slope .................................7-61
Crossing through shallow water ..........7-65
Riding over rough terrain ....................7-69
Sliding and skidding ............................7-71
What to do if ........................................7-75
What to do...........................................7-75
67
PERIODIC MAINTENANCE AND
ADJUSTMENT ......................................... 8-1
Owner’s manual and tool kit ................. 8-3
Periodic maintenance/lubrication.......... 8-7
Engine oil ............................................ 8-13
Final gear oil ....................................... 8-21
Spark plug inspection ......................... 8-27
Air filter element cleaning ................... 8-31
Carburetor adjustment ....................... 8-37
Idle speed adjustment ........................ 8-39
Valve clearance adjustment .............. 8-41
Throttle lever adjustment ................... 8-41
Front brake pad check ........................ 8-43
Rear brake shoe inspection ............... 8-43
Brake fluid level check ........................ 8-45
Brake fluid replacement ...................... 8-47
Front brake lever free play.................. 8-49
Rear brake adjustment ....................... 8-51
Adjusting the rear brake light switch ... 8-57
Clutch adjustment .............................. 8-59
Cable inspection and lubrication......... 8-61
Brake lever and brake pedal
lubrication ........................................ 8-63
Steering shaft lubrication .................... 8-63
Wheel removal.................................... 8-65
Wheel installation ............................... 8-67
Battery ............................................... 8-69
8
U4XE65.book Page 2 Tuesday, May 6, 2003 1:38 PM
Page 122 of 376
5-13
EBU10842
Engine oil
Make sure the engine oil is at the specified level.
Add oil as necessary. (See pages 8-13–8-19.)CAUTION:_
In order to prevent clutch slippage (since
the engine oil also lubricates the clutch),
do not mix any chemical additives. Do not
use oils with a diesel specification of “CD”
or oils of a higher quality than specified. In
addition, do not use oils labeled “ENERGY
CONSERVING II” or higher.
Make sure that no foreign material enters
the crankcase.
_
Recommended engine oil type and quantity:
See page 10-2.
U4XE65.book Page 13 Tuesday, May 6, 2003 1:38 PM
Page 150 of 376
6-15 1. Shift pedal N. Neutral position
1. Pédale de sélection N. Point mort
1. Pedal del cambio N. Punto muerto
EBU02000
Shifting
This model has a 5-speed forward transmission
with centrifugal automatic clutch. The transmission
allows you to control the amount of power you
have available at a given speed or for starting ac-
celerating, climbing, etc. To shift into neutral, re-
turn the throttle lever to its original position and
repeatedly depress the shift pedal until it stops.CAUTION:_ Do not coast for long periods with the engine
off, and do not tow the machine a long dis-
tance. Even with gears in neutral, the transmis-
sion is only properly lubricated when the
engine is running. Inadequate lubrication may
damage the transmission. _
U4XE65.book Page 15 Tuesday, May 6, 2003 1:38 PM
Page 208 of 376

7-37
With the engine idling, lift the shift pedal to the 1st
gear position and then release the parking brake.
Apply the throttle slowly and smoothly. The centrif-
ugal clutch will engage and you will start to accel-
erate. Once the ATV has attained adequate
speed, release the throttle and lift the shift pedal to
the 2nd gear position. Release the shift pedal and
apply the throttle smoothly. Use this same proce-
dure as you move into the higher gears. Be sure to
coordinate the use of the throttle and shift pedal
properly. If the throttle is applied too abruptly or if
the throttle is not released during shifting, or if the
shift pedal is not released before applying the
throttle, the front wheels may lift off the ground re-
sulting in a loss of directional control. Avoid higher
speeds until you are thoroughly familiar with the
operation of your ATV.CAUTION:_ Do not shift gears without releasing the throt-
tle. Damage to the engine or drive train may oc-
cur. _
U4XE65.book Page 37 Tuesday, May 6, 2003 1:38 PM
Page 258 of 376

8-7
EBU00262
PERIODIC MAINTENANCE/LUBRICATION
ITEM ROUTINEINITIAL EVERY
1
month3
months6
months6
months1
year
Valves*Check valve clearance.
Adjust if necessary.
Spark plugCheck condition.
Adjust gap and clean.
Replace if necessary.Air filter elementClean.
Replace if necessary.Every 20–40 hours
(More often in wet or dusty areas.)
Carburetor*Check starter (choke) operation.
Adjust engine idling speed.Cylinder head breather
system*Check breather hose for cracks or damage.
Replace if necessary.Exhaust system*Check for leakage.
Retighten if necessary.
Replace gasket if necessary.Fuel line*Check fuel hose for cracks or damage.
Replace if necessary.Engine oil
Replace (Warm engine before draining).Engine oil filter element
Clean.Engine oil strainer
Clean.Final gear oilCheck oil level/oil leakage.
Replace.Front brake*Check operation/fluid leakage/see NOTE page 8-8.
Correct if necessary.Rear brake*Check operation.
Adjust if necessary.Clutch*Check operation.
Adjust if necessary.U4XE65.book Page 7 Tuesday, May 6, 2003 1:38 PM
Page 310 of 376
8-59 1. Locknut 2. Adjusting bolt
1. Contre-écrou 2. Boulon de réglage
1. Contratuerca 2. Perno de ajuste
EBU00346
Clutch adjustment
1. Loosen the locknut.
2. Slowly turn the adjusting bolt counterclock-
wise until resistance is felt. Then, turn it 1/8
turn clockwise.
3. Tighten the locknut to specification.NOTE:Turn the adjusting bolt counterclockwise to de-
crease the clutch free play and turn it clockwise to
increase the free play.
Tightening torque:
15 Nm (1.5 m·kgf)
U4XE65.book Page 59 Tuesday, May 6, 2003 1:38 PM
Page 355 of 376
10-2
10
Starting system Electric starter and recoil starter
Lubrication system Wet sump
Engine oil:
Type
Recommended engine oil classification: API Service SE, SF, SG type or higher
Quantity:
Without oil filter element removal 1.5 L
With oil filter element removal 1.6 LModel YFM250X
-20˚ -10˚ 0˚
10˚20˚ 30˚40˚50˚C
10W/30
15W/4020W/4020W/50
10W/40
5W/30
CAUTION:
In order to prevent clutch slippage (since the en-
gine oil also lubricates the clutch), do not mix any
chemical additives. Do not use oils with a diesel
specification of “CD” or oils of a higher quality
than specified. In addition, do not use oils labeled
“ENERGY CONSERVING II” or higher.
U4XE65.book Page 2 Tuesday, May 6, 2003 1:38 PM
Page 356 of 376
10-3
Final gear oil:
Type SAE 80 API “GL-4” Hypoid gear oil
Quantity:
Periodic oil change 0.25 L
Air filter: Dry element
Fuel:
Type Unleaded gasoline only
For Europe: Regular unleaded gasoline only with
a research octane number of 91 or higher
Tank capacity 12 L
Reserve amount 1.6 L
Carburetor:
Ty p e
× quantity BST34
× 1
Manufacturer MIKUNI
Spark plug:
Type / manufacturer DR7EA / NGK
Gap 0.6–0.7 mm
Clutch type: Wet, centrifugal automaticModel YFM250X
U4XE65.book Page 3 Tuesday, May 6, 2003 1:38 PM