engine YAMAHA YFM600FWA 2001 Service Manual

8-17
2. Engine oil and oil filter replacement
a. Place the machine on a level place.
b. Remove the screw and the left side cover.
c. Warm up the engine for several minutes
and stop it.
d. Place a container under the engine and re-
move the oil filler cap.
1. Screw (× 3) 2. Cover
1. Vis (× 3) 2. Cache
1. Tornillo (× 3) 2. Tapa
1. Oil filler cap
1. Bouchon de remplissage d’huile
1. Tapa del orificio de llenado de aceite

8-23
j. Fill the engine with oil and install the oil
filler cap.
CAUTION:
Be sure no foreign material enters the crank-
case.
k. Warm up the engine for several min-
utes at idle speed. Check for oil leak-
age while warming up.
CAUTION:
If oil leakage is found, stop the engine immedi-
ately and check for the cause.Recommended oil:
See page 10-2.
Oil quantity:
Periodic oil change:
1.9 L
With oil filter replacement:
2.0 L
Total amount:
2.6 L

8-35
EBU00286
Spark plug inspection
The spark plug is an important engine compo-
nent and is easy to inspect. The condition of
the spark plug can indicate the condition of the
engine.
For example, a very white center electrode por-
celain color could indicate an intake air leak or
carburetion problem for that cylinder. Do not
attempt to diagnose such problems yourself.
Instead, take the machine to a Yamaha dealer.
You should periodically remove and inspect
the spark plug because heat and deposits will
cause the spark plug to slowly break down and
erode. If electrode erosion becomes excessive,
you should replace the spark plug with one of
the proper type.
Standard spark plug:
For Europe:
DPR8EA-9 (NGK)
For Oceania:
DPR8EA-9 (NGK)

8-41
3. Remove the air filter element, and sepa-
rate it from the guide.
4. Wash the element gently but thoroughly
in solvent.
WARNING
Always use parts cleaning solvent to clean the
air filter element. Never use low flash point
solvents or gasoline to clean the air filter ele-
ment because the engine could catch fire or
explode.
5. Squeeze the excess solvent out of the fil-
ter and let it dry.
CAUTION:
Do not twist the filter element when squeez-
ing it.
6. Inspect the element. If damaged, replace
it.
7. Apply SAE10W30 motor oil to the ele-
ment.
NOTE:
The element should be wet but not dripping.
1. Air filter
1. Filtre à air
1. Filtro de aire
1. Air filter guide
1. Guide de filtre à air
1. Filtro de aire guía

8-43
8. Reinstall the element to the element
guide.
9. Reinstall the element assembly and parts
removed for access.
NOTE:
The air filter element should be cleaned every
20 ~ 40 hours. It should be cleaned and lubri-
cated more often if the machine is operated in
extremely dusty areas. Each time filter element
maintenance is performed, check the air inlet
to the filter case for obstructions. Check the air
cleaner rubber joint to the carburetor and man-
ifold fittings for an air-tight seal. Tighten all fit-
tings securely to avoid the possibility of
unfiltered air entering the engine.
CAUTION:
Never operate the engine with the air filter el-
ement removed. This will allow unfiltered air
to enter, causing rapid engine wear and possi-
ble engine damage. Additionally, operation
without the filter element will affect carbure-
tor jetting with subsequent poor performance
and possible engine overheating.

8-45
EBU00296
Carburetor adjustment
The carburetor is a vital part of the engine and
requires very sophisticated adjustment. Most
adjusting should be left to a Yamaha dealer
who has the professional knowledge and expe-
rience to do so. However, the idling speed may
be performed by the owner as a part of the
usual maintenance routine.
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.

8-47
EBU00301
Idle speed adjustment
NOTE:
A diagnostic tachometer must be used for this
procedure.
1. Start the engine and warm it up for a few
minutes at approximately 1,000 to
2,000 r/min. Occasionally rev the engine
to 4,000 to 5,000 r/min. The engine is
warm when it quickly responds to the
throttle.
2. Connect the tachometer and set the idle to
the specified idling speed by adjusting the
throttle stop screw. Turn the screw in to
increase engine speed, and out to de-
crease engine speed.
Specified idle speed:
1,350 ~ 1,450 r/min
1. Throttle stop screw
1. Vis d’arrêt de l’accélérateur
1. Tornillo de tope del acelerador

8-49
EBU00303
Valve clearance adjustment
The correct valve clearance changes with use,
resulting in improper fuel/air supply or engine
noise. To prevent this, the valve clearance
must be adjusted regularly. This adjustment
however, should be left to a professional
Yamaha service technician.
EBU00307
Throttle lever adjustment
NOTE:
Adjust the engine idling speed before adjust-
ing the throttle lever free play.
1. Loosen the locknut.
2. Turn the adjusting bolt until the throttle le-
ver free play is 3 ~ 5 mm.
3. Tighten the locknut.
1. Locknut 2. Adjusting bolt a. Free play
1. Contre-écrou 2. Boulon de réglage a. Jeu
1. Contratuerca 2. Perno de ajuste a. Juego libre

8-69
EBU00570
Cable inspection and lubrication
WARNING
Inspect cables frequently and replace if dam-
aged. Corrosion can result when the outer
covering of control cables becomes damaged.
Cables can also become frayed or kinked. Op-
eration of controls could be restricted, which
could cause an accident or injury.
Lubricate the inner cables and the cable ends.
If the cables do not operate smoothly, ask a
Yamaha dealer to replace them.
EBU00717
Brake lever and brake pedal lubrication
Lubricate the pivoting parts.Recommended lubricant:
Engine oil
Recommended lubricant:
Lithium-soap-based grease
(all-purpose grease)

8-87
EBU00440
Troubleshooting chart
1. Fuel
Check if there is fuel
in the fuel tank.Enough fuelTurn the fuel
cock to “OFF”.Remove the fuel pipe
from the fuel cock. No fuelFuel cock
clogged
Clean fuel
cock. Some fuelTurn the fuel
cock to “RES”.Restart engine.
No fuel
Supply fuel
2. Compression
Use the electric
starter to see if there
is compression.Compression
Compression normal
No compression
Ask a Yamaha dealer to inspect.
3. Ignition
Remove the plug and
check the electrode.WetWipe clean with
dry cloth.
DryAttach plug cap and
ground to chassis.Use the
electric starter.Spark goodIgnition 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.
Recharge, check
connections.
Check fuel
flow Turn the fuel
cock to “ON”.