2003 YAMAHA YFM350R check engine

8-23
CAUTION:_

In order to prevent clutch slippage (since
the engine oil also lubricates the clutch),
do not mix any chemical additives. Do not
use oils with a diesel specification of
“CD” or oils of a higher quality than spec-
ified. In addition, do not use oils labeled
“ENERGY CONSERVING II” or higher.


Make sure that no foreign material enters
the crankcase.
_12. Start the engine, and then let it idle for seve-
ral minutes while checking it for oil leakage. If
oil is leaking, immediately turn the engine off
and check for the cause.
13. Turn the engine off, and then check the oil
level and correct it if necessary.
U5NF62.book Page 23 Wednesday, May 8, 2002 1:40 PM

8-29 1. Check hose
1. Flexible de contrôle
1. Manguito de comprobación
1. Air filter case cover
2. Screw (× 5)
1. Couvercle du boîtier de filtre à air
2. Vis (× 5)
1. Tapa de la caja del filtro de aire
2. Tornillo (× 5)
EBU01184
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 4-27 for seat re-
moval and installation procedures.)
2. Remove the air filter case cover by removing
the screws.
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. _
U5NF62.book Page 29 Wednesday, May 8, 2002 1:40 PM

8-33
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. _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. _
U5NF62.book Page 33 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