2003 YAMAHA BIG BEAR PRO 400 engine

6-23
EBU00209
Engine break-in
There is never a more important period in the life of
your machine than the period between zero and
20 hours.
For this reason, we ask that you carefully read the
following material. Because the engine is brand
new, you must not put an excessive load on it for
the first several hours of running. During the first
20 hours, the various parts in the engine wear and
polish themselves to the correct operating clear-
ances.
During this period, prolonged full throttle operation
or any condition which might result in excessive
engine heating must be avoided. However, mo-
mentary (2 ~ 3 seconds maximum) full throttle op-
eration under load does not harm the engine.
Each full throttle acceleration sequence should be
followed with a substantial rest period for the en-
gine by cruising at lower r/min so the engine can
rid itself of the temporary build up of heat.
If any abnormality is noticed during this period,
consult a Yamaha dealer.
EE.book Page 23 Monday, June 18, 2001 10:18 AM

6-27 1. Lock plate
1. Verrou de stationnement
1. Placa de bloqueo
EBU00211
Parking
When parking, stop the engine and shift into neu-
tral. Turn the fuel cock to “OFF” and apply the
parking brake.
EBU00220
Parking on a slope
WARNING
Avoid parking on hills or other inclines. Park-
ing on a hill or other incline could cause the
ATV to roll out of control, increasing the
chance of an accident. If you must park on an
incline, put the machine in low gear, apply the
parking brake, and block the front and rear
wheels with rocks or other objects.
Do not park the ATV at all on hills that are so
steep you could not walk up them easily.1. Bring the machine to a stop by applying the
brakes in low gear.
2. Stop the engine.
3. With the rear brake lever and pedal applied,
apply the parking brake and slowly release
the rear brake pedal.
EE.book Page 27 Monday, June 18, 2001 10:18 AM

7-7
Riding your machine requires skills acquired
through practice over a period of time.
Take the time to learn the basic techniques well
before attempting more difficult maneuvers.
Not recommended for children under 16 years
of age.
WARNING
A child under 16 should never operate an ATV
with engine size greater than 90 cc. Use by
children of ATVs that are not recommended for
their age can lead to severe injury or death of
the child.
EE.book Page 7 Monday, June 18, 2001 10:18 AM

7-35
Select a large, flat area off-road to become familiar
with your ATV. Make sure that this area is free of
obstacles and other riders. You should practice
control of the throttle, brakes, shifting procedures,
and turning techniques in this area before trying
more difficult terrain. Always avoid riding on paved
surfaces: the ATV is designed for off-road use
only, and handling maneuvers are more difficult to
perform on pavement.
Set the parking brake and follow the instruction on
page 6-3 to start the engine. Once it has warmed
up you are ready to begin riding your ATV. As you
get on the ATV, be sure not to accidentally move
the shift pedal. Remember that the engine and ex-
haust pipe will be hot when riding and afterwards;
do not allow skin or clothing to come in contact
with these components.
EE.book Page 35 Monday, June 18, 2001 10:18 AM

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.
EE.book Page 37 Monday, June 18, 2001 10:18 AM

7-39
When slowing down or stopping, release the throt-
tle and apply the brakes smoothly and evenly. As
you slow down, shift to a lower gear. Be sure that
the engine has sufficiently slowed before engaging
a lower gear. Improper use of the brakes or shift-
ing can cause the tires to lose traction, reducing
control and increasing the possibility of an acci-
dent.
WARNING
Make sure the engine has sufficiently slowed
before shifting to a lower gear. Engaging a low-
er gear when the engine speed is too high
could cause the wheels to stop rotating.
EE.book Page 39 Monday, June 18, 2001 10:18 AM

7-57
RIDING DOWNHILL
When riding your ATV downhill, shift your weight
as far to the rear and uphill side of the ATV as pos-
sible. Move back on the seat and sit with your
arms straight. Choose a low gear which will allow
the engine compression to do most of the braking
for you. Improper braking may cause a loss of trac-
tion.
Use caution while descending a hill with loose or
slippery surfaces. Braking ability and traction may
be adversely affected by these surfaces. Improper
braking may also cause a loss of traction.
Whenever possible, ride your ATV straight down-
hill. Avoid sharp angles which could allow the ATV
to tip or roll over. Carefully choose your path and
ride no faster than you will be able to react to ob-
stacles which may appear.
EE.book Page 57 Monday, June 18, 2001 10:18 AM

8-1
EBU00516
1-PERIODIC MAINTENANCE AND
ADJUSTMENTPeriodic inspection, adjustment and lubrication will
keep your machine in the safest and most efficient
condition possible. Safety is an obligation of the
machine owner. The most important points of ma-
chine inspection, adjustment and lubrication are
explained on the following pages.
WARNING
Never service an engine while it is running.
Moving parts can catch clothing or parts of the
body, causing injury. Electrical components
can cause shocks or can start fires. Turn off
the engine when performing maintenance un-
less otherwise specified. Have a Yamaha deal-
er perform service if you are not familiar with
machine service.
EE.book Page 1 Monday, June 18, 2001 10:18 AM