2008 YAMAHA YFM350R engine

7-6
7Speed limiter
For riders less experienced with this model, the
throttle lever housing is equipped with a speed lim-
iter. The speed limiter keeps the throttle from fully
opening, even when the throttle lever is pushed to
the maximum. Turning in the adjusting screw limits
the maximum engine power available and de-
creases the maximum speed of the ATV. Turning
in the adjusting screw decreases top speed, and
turning it out increases top speed. (See page 4-4.)Loading and accessories
As originally equipped, this ATV is not designed to
carry cargo or tow a trailer. If you choose to add ac-
cessories so that you can carry cargo or tow a trail-
er, you must use common sense and good
judgment.
Use extra caution when riding the ATV with addi-
tional loads, such as accessories or cargo. The
ATV’s handling may be adversely affected. Re-
duce your speed when adding additional loads.
WARNING
EWB01460
Never exceed the stated load capacity for
this ATV.
Cargo should be properly distributed and se-
curely attached.
Reduce speed when carrying cargo or pull-
ing a trailer. Allow greater distance for brak-
ing.
1. Adjusting screw
MAXIMUM LOADING LIMIT
ATV loading limit (total weight of cargo, rider,
accessories, and tongue):
100.0 kg (220 lb)
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7-12
7Select a large, flat, unpaved area to become famil-
iar 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 use on unpaved
surfaces only, and handling maneuvers are more
difficult to perform on pavement.
Set the parking brake and follow the instruction on
page 6-1 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.
With the engine idling, pull the clutch lever to dis-
engage the clutch and shift into 1st gear, and then
release the parking brake. Open the throttle grad-
ually, and at the same time, release the clutch le-
ver slowly. Once the ATV has attained adequate
speed, release the throttle lever and at the same
time, quickly pull in the clutch lever and shift into
2nd gear. Open the throttle part way and gradually
release the clutch. Use this same procedure as
you move into the higher gears. Be sure to coordi-
nate 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, resulting in a
loss of directional control. Avoid higher speeds un-
til you are thoroughly familiar with the operation of
your ATV.
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7-13
7
WARNING
EWB01720Always open the throttle gradually and release
the clutch lever slowly. Otherwise, the ATV
could wheelie which would increase thechance of an accident.CAUTION:ECB00230Do not shift gears without releasing the throt-
tle. Damage to the engine or drive train may oc-cur.
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 shifting
can cause the tires to lose traction, reducing con-
trol and increasing the possibility of an accident.
WARNING
EWB01560Make sure the engine has sufficiently slowed
before shifting to a lower gear. Engaging a low-
er gear when the engine speed is too highcould cause the wheels to stop rotating.TURNING YOUR ATV
To achieve maximum traction on unpaved surfac-
es, the two rear wheels are mounted solidly on one
axle and turn together at the same speed. There-
fore, unless the wheel on the inside of the turn is al-
lowed to slip or lose some traction, the ATV will
resist turning. A special turning technique must be
used to allow the ATV to make turns quickly and
easily. It is essential that this skill be learned first at
low speed.
WARNING
EWB01570Always follow proper procedures for turning
as described in this Owner’s Manual. Practice
turning at low speeds before attempting to turn
at faster speeds. Do not turn at speeds too fastfor your skills or the conditions.
As you approach a curve, slow down and begin to
turn the handlebars in the desired direction. As you
do so, put your weight on the footboard to the out-
side of the turn (opposite your desired direction)
and lean your upper body into the turn. Use the
throttle to maintain an even speed through the turn.
This maneuver will let the wheel on the inside of
the turn slip slightly, allowing the ATV to make the
turn properly.
U5YT64E0.book Page 13 Monday, April 9, 2007 1:03 PM

8-1
8
EBU28781
PERIODIC MAINTENANCE AND MINOR REPAIR
EBU21670Safety is an obligation of the owner. Periodic in-
spection, adjustment and lubrication will keep your
ATV in the safest and best operating condition
possible. The most important points of inspection,
adjustment, and lubrication are explained on the
following pages.
The intervals given in the periodic maintenance
and lubrication chart should be considered as a
general guide under normal riding conditions.
However, DEPENDING ON THE WEATHER,
TERRAIN, GEOGRAPHICAL LOCATION, AND
INDIVIDUAL USE, THE MAINTENANCE INTER-
VALS MAY NEED TO BE SHORTENED.
WARNING
EWB01840Never 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 start fires. Turn off the en-
gine when performing maintenance unlessotherwise specified. Have a Yamaha dealer
perform the service if you are not familiar with
maintenance work.EBU21690Owner’s manual and tool kit Be sure to put this owner’s manual and the low-
pressure tire gauge in the plastic bag and always
carry them along with the owner’s tool kit under the
seat.1. Owner’s tool kit
2. Owner’s manual
3. Low-pressure tire gauge
U5YT64E0.book Page 1 Monday, April 9, 2007 1:03 PM

8-3
8
EBU21742Periodic maintenance chart for the emission control system 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 inter-
vals. However, keep in mind that if the ATV isn’t used for a long period of time, the month maintenance
intervals should be followed.
Items marked with an asterisk should be performed by a Yamaha dealer as they require special tools,data and technical skills.NO. ITEMCHECK OR MAINTENANCE
JOBINITIAL EVERY
Whichev-
er comes
firstmonth136612
km
(mi)320
(200)1300
(800)2500
(1600)2500
(1600)5000
(3200)
hours 20 80 160 160 320
1*Fuel lineCheck fuel hoses for cracks or other damage, and
replace if necessary.√√√
2 Spark plugCheck condition and clean, regap, or replace if
necessary.√√√√√
3*ValvesCheck valve clearance and adjust if necessary.√ √√√
4*CarburetorCheck starter (choke) operation and correct if nec-
essary.
Check engine idling speed and adjust if neces-
sary.√√√√
5*Crankcase breather
systemCheck breather hose for cracks or other damage,
and replace if necessary.√√√
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8-6
8
10*Swingarm pivotsCheck operation and for excessive play, and re-
place bearings if necessary.
Lubricate with lithium-soap-based grease.√√√
11*Upper and lower
arm pivotsLubricate with lithium-soap-based grease.√√√
12 Drive chainCheck chain slack and adjust if necessary.
Check rear wheel alignment and correct if necess-
sary.
Clean and lubricate.√√√√√
13*Drive chain rollersCheck for wear and replace if necessary.√√√
14*Chassis fastenersMake sure that all nuts, bolts, and screws are
properly tightened.√√√√√
15*Shock absorber as-
sembliesCheck operation and correct if necessary.
Check for oil leakage and replace if necessary.√√√
16*Rear suspension re-
lay arm and con-
necting arm
pivoting pointsCheck operation and correct if necessary.
Lubricate with lithium-soap-based grease.√√√√
17*Steering shaftLubricate with lithium-soap-based grease.√√√
18*Steering systemCheck operation and repair or replace if damaged.
Check toe-in and adjust if necessary.√√√√√
19 Engine oilChange.
Check ATV for oil leakage, and correct if neces-
sary.√ √√√ NO. ITEMCHECK OR MAINTENANCE
JOBINITIAL EVERY
Whichev-
er comes
firstmonth136612
km
(mi)320
(200)1300
(800)2500
(1600)2500
(1600)5000
(3200)
hours 20 80 160 160 320U5YT64E0.book Page 6 Monday, April 9, 2007 1:03 PM

8-7
8
EBU23070NOTE:
The air filter needs more frequent service if you are riding in unusually wet or dusty areas.
Hydraulic brake service
Regularly check and, if necessary, correct the brake fluid level.
Every two years replace the internal components of the brake master cylinders and calipers, and
change the brake fluid.20Engine oil filter ele-
mentClean or replace if necessary.√√√
21 Engine oil strainerClean.√√√
22*Moving parts and
cablesLubricate.√√√√
23*Throttle lever hous-
ing and cableCheck operation and correct if necessary.
Check throttle cable free play and adjust if neces-
sary.
Lubricate throttle lever housing and cable.√√√√√
24*Front and rear brake
switchesCheck operation and correct if necessary.√√√√√
25*Lights and switchesCheck operation and correct if necessary.
Adjust headlight beams.√√√√√ NO. ITEMCHECK OR MAINTENANCE
JOBINITIAL EVERY
Whichev-
er comes
firstmonth136612
km
(mi)320
(200)1300
(800)2500
(1600)2500
(1600)5000
(3200)
hours 20 80 160 160 320U5YT64E0.book Page 7 Monday, April 9, 2007 1:03 PM

8-9
8
EBU23211Checking the spark plug The spark plug is an important engine component,
which is easy to check. Since heat and deposits
will cause any spark plug to slowly erode, the spark
plug should be removed and checked in accor-
dance with the periodic maintenance and lubrica-
tion chart. In addition, the condition of the spark
plug can reveal the condition of the engine.
To remove the spark plug
1. Remove the spark plug cap.2. Remove the spark plug as shown, with the
spark plug wrench included in the owner’s tool
kit.
To check the spark plug
1. Check that the porcelain insulator around the
center electrode of the spark plug is a medi-
um-to-light tan (the ideal color when the ATV
is ridden normally).
NOTE:If the spark plug shows a distinctly different color,
the engine could be operating improperly. Do not
attempt to diagnose such problems yourself. In-stead, have a Yamaha dealer check the ATV.
1. Spark plug cap
1. Spark plug wrench
U5YT64E0.book Page 9 Monday, April 9, 2007 1:03 PM