2005 YAMAHA BIG BEAR PRO 400 air filter

Tire wear limit......................................5-25
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
Reverse lock release wire ...................6-15
Shifting ................................................6-17
To start out and accelerate .................6-19
To decelerate ......................................6-21
Engine break-in ...................................6-23
Parking ................................................6-27
Parking on a slope ..............................6-27
Accessories and loading .....................6-29
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
67
Sliding and skidding............................ 7-71
What to do if ....................................... 7-75
What to do .......................................... 7-75
PERIODIC MAINTENANCE AND
ADJUSTMENT ......................................... 8-1
Owner’s manual and tool kit ................. 8-3
Periodic maintenance/lubrication.......... 8-7
Engine oil and oil filter element........... 8-17
Transfer gear oil replacement............. 8-29
Final gear oil ....................................... 8-33
Differential gear oil replacement ......... 8-39
Axle boots ........................................... 8-41
Spark plug inspection ......................... 8-43
Air filter cleaning ................................. 8-47
Carburetor adjustment ........................ 8-55
Idle speed adjustment ........................ 8-57
Valve clearance adjustment ............... 8-59
Select lever safety system cable
adjustment ........................................ 8-59
Throttle lever adjustment .................... 8-61
Front brake pad check ........................ 8-61
Rear brake shoe inspection ................ 8-63
Brake fluid level check ........................ 8-63
Brake fluid replacement ...................... 8-67
Front brake lever free play.................. 8-69
8
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7-67
1. Air filter case check hose
1. Flexible de contrôle du boîtier de filtre à air
1. Manguito de retención de la caja del filtro de aire
Test your brakes after leaving the water. Do not
continue to ride your ATV without verifying that
you have regained proper braking ability.CAUTION:_ After riding your ATV in water, be sure to drain
the trapped water by removing the check hose
at the bottom of the air filter case. Wash the
ATV in fresh water if it has been operated in
salt water or muddy conditions. _
U1C160.book Page 67 Wednesday, May 12, 2004 4:55 PM

8-7
EBU02621
PERIODIC MAINTENANCE/LUBRICATION
NOTE:_

For ATVs not equipped with an odometer or an hour meter, follow the month maintenance intervals.


For ATVs equipped with an odometer or an hour meter, follow the km (mi) or hours maintenance intervals. How-
ever, keep in mind that if the ATV isn’t used for a long period of time, the month maintenance intervals should be
followed.
_
ITEM ROUTINEWhichever
comes firstINITIAL EVERY
month136612
km
(mi)320
(200)1,200
(750)2,400
(1,500)2,400
(1,500)4,800
(3,000)
hours 20 75 150 150 300
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.Crankcase breather
system*Check breather hose for cracks or damage.
Replace if necessary.Exhaust system*Check for leakage.
Retighten if necessary.
Replace gasket(s) if necessary.Fuel line*Check fuel hose for cracks or damage.
Replace if necessary.Engine oil
Replace (Warm engine before draining).Transfer gear oilU1C160.book Page 7 Wednesday, May 12, 2004 4:55 PM

8-8
* Since these items require special tools, data and technical skills, have a Yamaha dealer perform the service.Engine oil filter element
Replace.Engine oil strainer
Clean.Final gear oil
Check oil level/oil leakage.
Replace every 12 months.Differential gear oil
Front brake*Check operation/fluid leakage/see NOTE page 8-9.
Correct if necessary.Rear brake*Check operation.
Adjust if necessary.Clutch*Check operation.
Adjust if necessary.Drive select lever
safety system*Check operation.
Adjust if necessary.Wheels*Check balance/damage/runout.
Repair if necessary.Wheel bearing*Check bearing assemblies for looseness/damage.
Replace if damaged.Steering system*Check operation.
Replace if damaged.
Check toe-in.
Adjust if necessary.Axle boots*Check condition.
Replace if damaged.Fittings and fasteners*Check all chassis fittings and fasteners.
Correct if necessary.
ITEM ROUTINEWhichever
comes firstINITIAL EVERY
month136612
km
(mi)320
(200)1,200
(750)2,400
(1,500)2,400
(1,500)4,800
(3,000)
hours 20 75 150 150 300
U1C160.book Page 8 Wednesday, May 12, 2004 4:55 PM

8-47 1. Air filter case check hose
1. Flexible de contrôle du boîtier du filtre à air
1. Manguito de retención de la caja del filtro de aire
1. Air filter case cover 2. Screw (× 4)
1. Cache du boîtier de filtre à air 2. Vis (× 4)
1. Tapa de la caja del filtro de aire 2. Tornillos (× 4)
EBU11840
Air filter cleaningNOTE:_ There is a check hose at the bottom of the air filter
case. If dust or water collects in this hose, empty
the hose and clean the air filter element and air fil-
ter case. _1. Remove the seat. (See page 4-35 for seat re-
moval and installation procedures.)
2. Remove the air filter case cover by removing
the screws.
U1C160.book Page 47 Wednesday, May 12, 2004 4:55 PM

8-49 1. Air filter element
1.Élément du filtre à air
1. Elemento del filtro de aire
1. Element retaining plate
2. Air filter element 3. Frame
1. Plaque de retenue
2.Élément du filtre à air 3. Armature
1. Placa de retención del elemento
2. Elemento del filtro de aire 3. Bastidor
3. Remove the air filter element.
4. Remove the air filter element from the frame.
5. Wash the air filter element gently but thor-
oughly in solvent.
WARNING
_ Always use parts cleaning solvent to clean the
air filter element. Never use low flash point sol-
vents or gasoline to clean the air filter element
because the engine could catch fire or ex-
plode. _6. Squeeze the excess solvent out of the air fil-
ter element and let it dry.CAUTION:_ Do not twist the air filter element when squeez-
ing it. _7. Inspect the air filter element. If damaged, re-
place it.
8. Apply SAE 10W30 engine oil to the air filter
element.NOTE:_ The air filter element should be wet but not drip-
ping. _
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8-51
9. Apply all-purpose grease to the air filter ele-
ment seat.
10. Install the air filter element on the frame.
11. Install the air filter element.
12. Install the air filter case cover by installing the
screws.
13. Install the seat.NOTE:_ The air filter element should be cleaned every 20–
40 hours. It should be cleaned and lubricated more
often if the machine is operated in extremely dusty
areas. Each time air filter element maintenance is
performed, check the air inlet to the air filter case
for obstructions. Check the air filter element rubber
joint to the carburetor and manifold fittings for an
airtight seal. Tighten all fittings securely to avoid
the possibility of unfiltered air entering the engine. _
U1C160.book Page 51 Wednesday, May 12, 2004 4:55 PM

8-53
CAUTION:_ Never operate the engine with the air filter ele-
ment removed. This will allow unfiltered air to
enter, causing rapid engine wear and possible
engine damage. Additionally, operation with-
out the air filter element will affect carburetor
jetting with subsequent poor performance and
possible engine overheating. _
U1C160.book Page 53 Wednesday, May 12, 2004 4:55 PM