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 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 266 of 376
8-15 1. Engine oil drain bolt 2. O-ring
3. Compression spring 4. Engine oil strainer
1. Boulon de vidange de l’huile moteur
2. Joint torique
3. Ressort de compression
4. Crépine à huile de moteur
1. Perno de drenaje del aceite de motor
2. Junta tórica
3. Muelle de compresión
4. Tamiz de aceite de motor
Engine oil replacement and oil filter element
cleaning
1. Place the machine on a level surface.
2. Warm up the engine for several minutes and
stop it.
3. Place a container under the engine to collect
the used oil.
4. Remove the engine oil filler cap and then the
drain bolt to drain the oil.CAUTION:_ When removing the drain bolt, the compres-
sion spring, oil strainer and O-ring will fall out.
Take care not to lose these parts. _
U4XE65.book Page 15 Tuesday, May 6, 2003 1:38 PM
Page 268 of 376
8-17 1. Oil filter cover
2. Engine oil filter element
3. O-ring
1. Couvercle du filtre à huile
2.Élément du filtre à huile de moteur
3. Joint torique
1. Tapa del filtro de aceite
2. Elemento del filtro de aceite de motor
3. Junta tórica
5. Remove the oil filter cover and oil filter ele-
ment.
6. Clean the oil strainer and oil filter element
with solvent.
7. Inspect the O-ring and replace it if damaged.
8. Install the oil filter element, O-ring and oil filter
cover.
9. Install the oil strainer, compression spring,
O-ring and drain bolt.
10. Tighten the drain bolt and the oil filter cover
bolts to the specified torques.CAUTION:_ Before installing the drain bolt, be sure to in-
stall the O-ring, compression spring and oil
strainer. _11. Fill the engine with oil and install the engine
oil filler cap. Tightening torque:
Drain bolt (engine):
43 Nm (4.3 m·kgf)
Oil filter cover bolt:
10 Nm (1.0 m·kgf)
U4XE65.book Page 17 Tuesday, May 6, 2003 1:38 PM
Page 270 of 376
8-19
CAUTION:_ Be sure no foreign material enters the crank-
case. _12. Warm up the engine for several minutes at
idle speed. Check for oil leakage while warm-
ing up.CAUTION:_ If oil leakage is found, stop the engine immedi-
ately and check for the cause. _
Recommended engine oil:
See page 10-2.
Oil quantity:
Without oil filter element removal:
1.5 L
With oil filter element removal:
1.6 L
U4XE65.book Page 19 Tuesday, May 6, 2003 1:38 PM
Page 284 of 376

8-33 1. Air filter element
1.Élément du filtre à air
1. Elemento del filtro de aire
1. Air filter element 2. Foam cover
1.Élément du filtre à air 2. Cache en mousse
1. Elemento del filtro de aire 2. Forro de espuma
3. Pull the air filter element out.
4. Remove the foam cover from the air filter ele-
ment.
5. Tap the air filter element lightly to remove
most of the dust and dirt. Blow out the re-
maining dirt with compressed air as shown. If
the air filter element is damaged, replace it.
6. Wash the foam cover gently but thoroughly in
water or solvent.
WARNING
_ When using solvent to clean the foam cover,
always use parts cleaning solvent. Never use
low flash point solvents or gasoline to clean
the foam cover because the engine could
catch fire or explode. _7. Squeeze the excess solvent out of the foam
cover and let it dry.CAUTION:_
Do not twist the foam cover when squeez-
ing it.
Do not apply oil to the foam cover.
_8. Check the foam cover. If damaged, replace it.
U4XE65.book Page 33 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