Page 94 of 134
8-17
814. Install the washer onto the air filter element
frame, and then insert the wing bolt into the
hole in the air filter element frame. NOTICE:
Be sure to install the washer with its
curved side facing outward as shown.
[ECB00453]
15. Insert the air filter element into the air filtercase, and then tighten the wing bolt. NOTICE:
Make sure that the air filter element is
properly seated in the air filter case. Never
operate the engine with the air filter ele-
ment removed. This will allow unfiltered air
to enter the engine, causing rapid engine
wear and possible engine damage. Addi-
tionally, operation without the air filter ele-
ment will affect carburetor jetting with
subsequent poor performance and possi-
ble engine overheating.
[ECB00461]
16. Install the air filter case cover by hooking the holders onto the air filter case.
1. Air filter element seat
1
1. Washer
1
U1BT62E0.book Page 17 Tuesday, April 19, 2011 7:06 PM
Page 95 of 134

8-18
8
17. Install the seat.
TIPThe air filter element should be cleaned every 20
–
40 hours. It should be cleaned and lubricated more
often if the ATV is operated in extremely dusty ar-
eas. Each time the air filter element maintenance
is performed, check the air inlet of the air filter case
for obstructions. Check the air filter case rubber
joint to the carburetor fittings and the rubber joint
manifold fittings for an air-tight seal. Tighten all fit-
tings securely to avoid the possibility of unfiltered
air entering the engine.EBU28903Cleaning the spark arrester Be sure the exhaust pipe and muffler are cool be-
fore cleaning the spark arrester. 1. Remove the tailpipe bolts. 2. Remove the tailpipe by pulling it out of the
muffler, and then remove the gasket.
3. Tap the tailpipe lightly, and then use a wire brush to remove any carbon deposits from the
spark arrester portion of the tailpipe and inside
of the tailpipe housing.
1. Tailpipe bolt
2. Tailpipe
2
1 1
U1BT62E0.book Page 18 Tuesday, April 19, 2011 7:06 PM
Page 126 of 134

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:
1.25 L (1.32 US qt, 1.10 Imp.qt)
With oil filter element replacement: 1.35 L (1.43 US qt, 1.19 Imp.qt)Air filter:Air filter element:
Wet elementFuel:Recommended fuel:YFM250RB Unleaded gasoline only
YFM25RB Regular unleaded gasoline only Fuel tank capacity:
9.0 L (2.38 US gal, 1.98 Imp.gal)
Fuel reserve amount: 1.0 L (0.26 US gal, 0.22 Imp.gal)
Carburetor:Type × quantity:
BSR29 x 1Spark plug (s):Manufacturer/model:
NGK/DR7EA
Spark plug gap: 0.6 –0.7 mm (0.024 –0.028 in)Clutch:Clutch type:
Wet, multiple-disc
Operation: Left hand operationTransmission:Primary reduction system:
Spur gear
Primary reduction ratio: 76/22 (3.455)
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
U1BT62E0.book Page 2 Tuesday, April 19, 2011 7:06 PM
Page 132 of 134

INDEX
AAccessories and loading ................................................ 6-6
Air filter element, cleaning ............................................ 8-14BBattery .......................................................................... 8-35
Brake and clutch levers, checking and lubricating ....... 8-32
Brake fluid, changing .................................................... 8-25
Brake fluid level, checking ............................................ 8-23
Brake lever ..................................................................... 4-5
Brake lever free play, checking the front ...................... 8-25
Brake light switches ..................................................... 8-27
Brake pads, checking the front and rear ...................... 8-22
Brake pedal .................................................................... 4-5
Brake pedal, checking and lubricating ......................... 8-33
Brake pedal height, checking ....................................... 8-25
Brakes .......................................................................... 8-22
Brakes, front and rear .................................................... 5-3CCables, checking and lubricating ................................. 8-31
Carburetor, adjusting .................................................... 8-20
Chassis fasteners ........................................................... 5-6
Cleaning ......................................................................... 9-1
Clutch lever .................................................................... 4-4
Clutch lever free play, adjusting ................................... 8-28DDrive chain ..................................................................... 5-4
Drive chain, lubricating ................................................. 8-31
Drive chain slack .......................................................... 8-29
EEngine break-in .............................................................. 6-4
Engine, cold start ........................................................... 6-1
Engine idling speed ...................................................... 8-20
Engine oil ....................................................................... 5-3
Engine oil and oil filter element .................................... 8-11
Engine, starting a warm ................................................. 6-2
Engine stop switch ......................................................... 4-2FFuel ......................................................................... 4-8, 5-3
Fuel cock ........................................................................ 4-9
Fuel tank cap .................................................................. 4-7
Fuse, replacing ............................................................. 8-38HHandlebar switches ........................................................ 4-2
Headlight beam, adjusting ............................................ 8-41
Headlight bulb, replacing .............................................. 8-39IIdentification numbers .................................................. 11-1
Indicator light .................................................................. 4-2
Instruments, lights and switches .................................... 5-6LLabel locations ............................................................... 1-1
Light switch .................................................................... 4-3MMain switch .................................................................... 4-1
Maintenance and lubrication chart ................................. 8-5
Maintenance chart, emission control system ................. 8-3
U1BT62E0.book Page 1 Tuesday, April 19, 2011 7:06 PM