2004 YAMAHA BLASTER 200 engine

8-23
7. Start the engine and warm it up for a few
minutes. While warming up, check for oil
leakage. If oil leakage is found, stop the
engine immediately, and check for the
cause.
8. Check the oil level.
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8-27
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.
The ideal color on the white insulator around the
center electrode is a medium-to-light tan color
for a ATV that is being ridden normally.
Do not attempt to diagnose such problems your-
self.
Instead, take the ATV 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, or if
carbon and other deposits are excessive, you
should replace the spark plug with the specified
plug.
Standard spark plug:
BR8ES (NGK)
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8-33
3. Remove the air filter element, and separate
the sponge material from its frame by
removing the screw.
4. Wash the sponge material gently but thor-
oughly in solvent.
w
Always use parts cleaning solvent to clean
the sponge material. Never use low flash
point solvents or gasoline to clean the
sponge material because the engine could
catch fire or explode.
5. Squeeze the excess solvent out of the
sponge material and let it dry.
cC
Do not twist the sponge material when
squeezing it.
q
w
1. Sponge material 2. Frame1. Mousse 2. Armature1. Material esponjoso 2. Marco
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8-35
6. Inspect the sponge material. If damaged,
replace it.
7. Apply SAE 10W30 engine oil to the sponge
material.
NOTE:
The sponge material should be wet but not drip-
ping.
8. Install the sponge material onto its frame
and install the screw.
9. Install the air filter element.
10. Install the air filter case cover by installing
the screws.
11. Install the seat.
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8-37
NOTE:
The sponge material should be cleaned every
20–40 hours. It should be cleaned and lubricat-
ed more often if the machine is operated in
extremely dusty areas. Each time air filter ele-
ment maintenance is performed, check the air
inlet to the filter case for obstructions. Check the
air filter case rubber joint to the carburetor and
manifold fittings for an air-tight seal. Tighten all
fittings securely to avoid the possibility of unfil-
tered air entering the engine.
cC
Never operate the engine with the air filter
element removed. This will allow unfiltered
air to enter, causing rapid engine wear and
possible engine damage. Additionally, opera-
tion without the air filter element will affect
carburetor jetting with subsequent poor per-
formance and possible engine overheating.
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8-39
EBU12831
Carburetor settings
In extremely cold weather, it is necessary to
change the carburetor settings to maintain opti-
mum engine performance and to prevent engine
damage.
w
8Improperly servicing or adjusting the car-
buretor could cause malfunction with the
possibility of an accident or the carburetor
could leak fuel, which would be a fire haz-
ard.
8Carburetor adjustments should only be
performed by a Yamaha dealer. Do not
attempt to perform these procedures
unless you have mechanical knowledge
and the necessary tools.
8Do not perform this procedure while the
engine is hot. Place a rag under the carbu-
retor to catch any fuel. Wipe up any spilled
fuel completely.
8After servicing the carburetor, always
check throttle operation before operating
the ATV to make sure it is working correct-
ly.
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8-51
EBU13020
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 to the spark plug
lead, and then set the idle to the specified
idling speed by adjusting the throttle stop
screw. Turn the screw in direction ato
increase the engine speed, and in direction
bto decrease the engine speed.
1
a
b
1. Throttle stop screw1. Vis d’arrêt de l’accélérateur1. Tornillo tope del acelerador
Specified idle speed:
1,450–1,550 r/min
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8-53
EBU00307
Throttle lever adjustment
NOTE:
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 4–6 mm.
3. Tighten the locknut.
qw
a
1. Adjusting bolt 2. Locknut a. Free play1. Boulon de réglage 2. Contre-écrou a. Jeu1. Perno de ajuste 2. Contratuerca a. Juego libre
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