2002 YAMAHA BEAR TRACKER 250 Carburetor

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
67
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 ............................................ 8-13
Final gear oil ....................................... 8-23
Spark plug inspection ......................... 8-29
Air filter cleaning ................................. 8-33
Carburetor adjustment ....................... 8-39
Idle speed adjustment ....................... 8-41
Valve clearance adjustment .............. 8-43
Throttle lever adjustment ................... 8-43
Front brake pad inspection ................ 8-45
Rear brake shoe inspection ............... 8-45
Brake fluid level inspection ................ 8-47
Brake fluid replacement ...................... 8-49
Front brake adjustment ...................... 8-51
Rear brake adjustment ...................... 8-53
Adjusting the rear brake light switch ... 8-59
Clutch adjustment .............................. 8-61
Cable inspection and lubrication......... 8-63
Brake lever and brake pedal
lubrication ........................................ 8-65
Steering shaft lubrication ................... 8-65
8
EE.book Page 2 Monday, June 25, 2001 3:46 PM

2-17
WARNING


Always turn off the engine when refueling.


Do not refuel right after the engine has
been running and is still very hot.


Do not spill gasoline on the engine or ex-
haust pipe/muffler when refueling. Never
refuel while smoking, or while in the vicini-
ty of sparks, open flames, or other sources
of ignition such as the pilot lights of water
heaters and clothes dryers. Gasoline can
catch fire and you could be burned.


When transporting the machine in another
vehicle, be sure it is kept upright and that
the fuel cock is in the “OFF” position. Oth-
erwise, fuel may leak out of the carburetor
or fuel tank.


Gasoline is poisonous. If you should swal-
low some gasoline or inhale a lot of gaso-
line vapor, or get some gasoline in your
eyes, see your doctor immediately. If gaso-
line spills on your skin, wash with soap
and water. If gasoline spills on your cloth-
ing, change your clothes.
EE.book Page 17 Monday, June 25, 2001 2:27 PM

4-21
EBU00093
Fuel cock
The fuel cock supplies fuel from the fuel tank to the
carburetor.
The fuel cock has three positions.
OFF: With the lever in this position fuel will not
flow. Always turn the lever to this position
when the engine is not running.
ON: With the lever in this position, fuel flows to
the carburetor. Normal riding is done with
the lever in this position.
RES: This indicates reserve. If you run out of fuel
while riding, turn the lever to this position.
THEN FILL THE FUEL TANK AT THE
FIRST OPPORTUNITY. After refuelling, re-
turn the fuel cock lever to the “ON” position.
EE.book Page 21 Monday, June 25, 2001 2:27 PM

8-7
EBU00262
PERIODIC MAINTENANCE/LUBRICATION
ITEM ROUTINEINITIAL EVERY
1
month3
months6
months6
months1
year
Valves*•Check valve clearance.
•Adjust if necessary.
Spark plug•Check condition.
•Adjust gap and clean.
•Replace if necessary.Air filter•Clean.
•Replace if necessary.Every 20~40 hours
(More often in wet or dusty areas.)
Carburetor*•Check idle speed/starter operation.
•Adjust if necessary.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
•Clean.Engine oil strainer
•Clean.Final gear oil•Check oil level/oil leakage.
•Replace.Front brake*•Check operation/fluid leakage/see NOTE page 8-4.
•Correct if necessary.Rear brake*•Check operation.
•Adjust if necessary.Clutch*•Check operation.
•Adjust if necessary.EE.book Page 7 Monday, June 25, 2001 2:27 PM

8-37 1. Air filter element 2. Foam cover
1.Élément du filtre à air 2. Cache en mousse
1. Elemento filtrante 2. Forro de espuma
9. Reinstall the foam cover to the air filter ele-
ment.
10. Reinstall the air filter assembly and parts re-
moved for access.NOTE:_ The air filter element should be cleaned every 20 ~
40 hours. It should be cleaned more often if the
machine is operated in extremely dusty areas.
Each time filter element maintenance is per-
formed, check the air inlet to the filter case for ob-
structions. Check the air cleaner 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. _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 filter element will affect carburetor jet-
ting with subsequent poor performance and
possible engine overheating. _
EE.book Page 37 Monday, June 25, 2001 2:27 PM

8-39
EBU00296
Carburetor adjustment
The carburetor is a vital part of the engine and re-
quires very sophisticated adjustment. Most adjust-
ing should be left to a Yamaha dealer who has the
professional knowledge and experience to do so.
However, the idling speed may be performed by
the owner as a part of the usual maintenance rou-
tine.CAUTION:
The carburetor was set at the Yamaha factory
after many tests. If the settings are disturbed
by someone without sufficient technical
knowledge, poor engine performance and
damage may result.
EE.book Page 39 Monday, June 25, 2001 2:27 PM

10-4
Carburetor:
Type / manufacturer BST34/1/MIKUNI
Spark plug:
Type / manufacturer DR7EA / NGK
Gap 0.6 ~ 0.7 mm
Clutch type: Wet, centrifugal automatic
Transmission:
Primary reduction system Spur gear
Primary reduction ratio 73/22 (3.318)
Secondary reduction system Shaft drive
Secondary reduction ratio 19/18
× 46/11 (4.414)
Transmission type Constant mesh, 5-speed forward, 1-speed reverse
Operation Left foot operation
Gear Ratio:
1st 34/12 (2.833)
2nd 34/19 (1.789)
3rd 29/22 (1.318)
4th 26/25 (1.040)
5th 23/28 (0.821)
Reverse 73/22
× 34/12
× 19/18 (9.924) Model YFM250X
EE.book Page 4 Monday, June 25, 2001 2:27 PM