2003 YAMAHA YFM350R fuel

6-3
EBU00514
Starting a cold engine
WARNING
_ Always make sure all control cables work
smoothly before you begin riding in cold
weather. If the control cables are frozen or do
not work smoothly, you could be unable to
control the ATV, which could lead to an acci-
dent or collision. _ 1. Set the parking brake.
2. Turn the fuel cock to “ON”.
3. Turn the main switch to “ON” and the engine
stop switch to “RUN”.
4. Shift the transmission into neutral.
U5NF62.book Page 3 Wednesday, May 8, 2002 1:40 PM

6-27 1. Button 2. Lock plate
1. Bouton 2. Verrou
1. Botón 2. Placa de bloqueo
1. Locked position
1. Position verrou bloqué
1. Posición bloqueada
EBU00211
Parking
When parking, stop the engine and shift into neu-
tral. Turn the fuel cock to “OFF” and apply the
parking brake.
U5NF62.book Page 27 Wednesday, May 8, 2002 1:40 PM

8-7
EBU00262
5-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 element•Clean.
•Replace if necessary.Every 20–40 hours
(More often in wet or dusty areas.)
Carburetor*•Check idle speed/starter operation.
•Adjust if necessary.Crankcase breather
system*•Check breather hose for cracks or damage.
•Replace if necessary.Exhaust system*•Check for leakage.
•Tighten 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.)Engine oil filter element•Clean.
•Replace if necessary.Engine oil strainer•Clean.Drive chain•Check and adjust slack/alignment/clean/lube.Brakes*•Check operation/fluid leakage/See NOTE page 8-8.
•Correct if necessary.Clutch*•Check operation.
•Adjust if necessary.Wheels*•Check balance/damage/runout.
•Replace if necessary.U5NF62.book Page 7 Wednesday, May 8, 2002 1:40 PM

8-39 1. Locknut 2. Adjusting bolt
a. Throttle lever free play
1. Contre-écrou 2. Boulon de réglage
a. Jeu du levier d’accélération
1. Contratuerca 2. Perno de ajuste
a. Juego libre de la palanca del acelerador
EBU00307
Throttle lever adjustmentNOTE:Adjust the engine idling speed before adjusting the
throttle lever free play.1. Loosen the locknut.
2. Turn the adjusting bolt until the throttle lever
free play is 3–5 mm.
3. Tighten the locknut.
EBU00303
Valve clearance adjustment
The correct valve clearance changes with use, re-
sulting in improper fuel/air supply or engine noise.
To prevent this, the valve clearance must be ad-
justed regularly. This adjustment however, should
be left to a professional Yamaha service techni-
cian.
U5NF62.book Page 39 Wednesday, May 8, 2002 1:40 PM

8-99
EBU00413
Troubleshooting
Although Yamaha machines receive a rigid in-
spection before shipment from the factory, trouble
may occur during operation.
Any problem in the fuel, compression, or ignition
systems can cause poor starting and loss of pow-
er. The troubleshooting chart describes a quick,
easy procedure for making checks. If your ma-
chine requires any repair, take it to a Yamaha
dealer.
The skilled technicians at a Yamaha dealership
have the tools, experience, and know-how to prop-
erly service your machine. Use only genuine
Yamaha parts on your machine. Imitation parts
may look like Yamaha parts, but they are often in-
ferior. Consequently, they have a shorter service
life and can lead to expensive repair bills.
WARNING
Do not smoke when checking the fuel system.
Fuel can ignite or explode, causing severe in-
jury or property damage. Make sure there are
no open flames or sparks in the area, including
pilot lights from water heaters or furnaces.
U5NF62.book Page 99 Wednesday, May 8, 2002 1:40 PM

8-101
EBU00440*
Troubleshooting chart1. Fuel
Check if there is fuel
in the fuel tank.There is fuel.Turn the fuel
cock to “OFF”.No fuel.Fuel cock
clogged.
Clean fuel
cock. Some fuel.Turn the fuel
cock to “RES”.Restart engine.
No fuel.Supply fuel.
2. Compression
Use the electric starter
to see if there is
compression.There is compression.
Compression normal.
No compression.Ask a Yamaha dealer to
inspect.
3. Ignition
Remove plug and
check electrodes.WetWipe clean with dry cloth.
DryAttach plug cap and
ground to chassis.Use the
electric starter.Spark good.Ignition system
normal.
Spark weak.
Adjust plug gap
or replace plug. No spark.
Ask a Yamaha dealer to
inspect. 4. Battery
Use the electric
starter.Engine turns over
quickly.Battery good.
Engine turns over
slowly.Check fluid, recharge,
check connections.Check fuel
flow.
Turn the fuel
cock to “ON”.
Remove the
fuel hose.
U5NF62.book Page 101 Wednesday, May 8, 2002 1:40 PM

9-7
EBU00526
B. STORAGE
Long term storage (60 days or more) of your ma-
chine will require some preventive procedures to
guard against deterioration. After thoroughly
cleaning the machine, prepare for storage as fol-
lows:
1. Fill the fuel tank with fresh fuel and add fuel
stabilizer (if available).NOTE:Use of fuel stabilizer eliminates the need to drain
the fuel system. Consult a Yamaha dealer if the
fuel system is to be drained instead.2. Remove the spark plug, pour about one ta-
blespoon of SAE 10W30 or 20W40 motor oil
in the spark plug hole and reinstall the spark
plug. Ground the spark plug wire and turn the
engine over several times to coat the cylinder
wall with oil.
3. Clean the drive chain thoroughly and lubri-
cate it. (See page 8-65.)
4. Lubricate all control cables.
U5NF62.book Page 7 Wednesday, May 8, 2002 1:40 PM

10-1
EBU00428
SPECIFICATIONS
MODEL YFM350X
Dimension:
Overall length
Overall width
Overall height
Seat height
Wheel base
Ground clearance
Minimum turning radius1,840 mm
1,080 mm
1,080 mm
765 mm
1,200 mm
125 mm
3,500 mm
Basic weight:
With oil and full fuel tank 191 kg
Engine:
Type
Cylinder arrangement
Displacement
Bore
× Stroke
Compression ratio
Starting system
Lubrication systemAir-cooled, 4-stroke, SOHC
Forward inclined single cylinder
348 cm
3
83.0
× 64.5 mm
9.2 : 1
Electric starter
Wet sump
U5NF62.book Page 1 Wednesday, May 8, 2002 1:40 PM