how to synchronize your throttle bodie....

[trophytaker308]

SYNCHRONIZING THE THROTTLE BODIES
NOTE:
Prior to synchronizing the throttle bodies, the
valve clearance and the engine idling speed
should be properly adjusted.

1. Stand the vehicle on a level surface.
NOTE:
Place the vehicle on a suitable stand.
2. Remove:
• Rider seat
Refer to “GENERAL CHASSIS” on page 4-1.
• Fuel tank
Refer to “FUEL TANK” on page 7-1.
3. Remove:
• Caps “1”
4. Install:
• Vacuum gauge “1”
• Digital tachometer
Vacuum gauge
90890-03094
Carburetor synchronizer
YU-44456
5. Install:
• Fuel tank
Refer to “FUEL TANK” on page 7-1.
6. Adjust:
• Throttle body synchronization

Basic procedure
a. Start the engine, warm it up for several minutes,
and then let it run at the specified engine
idling speed.
Engine idling speed
1250–1350 r/min

b. Turn the bypass air screw “1” with a white
paint mark out a little, and then turn it in fully.
c. Using the throttle body that has the bypass air
screw with a white paint mark as the standard,
turn the bypass air screws without white
paint marks in or out to the adjust the other
throttle bodies.
NOTE:
• If more than one throttle body has a bypass air
screw with a white paint mark, use the one with
the lowest vacuum pressure as the standard.
• After each step, rev the engine two or three
times, each time for less than a second, and
check the synchronization again.
• If an air screw was removed, turn the screw 3/4
turn in and be sure to synchronize the throttle
body.
Intake vacuum
20.0 kPa (5.9 inHg) (150 mmHg)
NOTE:
• The difference in vacuum pressure between
two throttle bodies should not exceed 1.33 kPa
(10 mmHg).
• If you are unable to adjust the throttle body
synchronization using this procedure, use the
following procedure instead.

Alternate procedure
NOTE:
Use this alternate procedure if you are unable to
adjust the throttle body synchronization using
the basic procedure.
a. Start the engine, warm it up for several minutes,
and then let it run at the specified engine
idling speed.

b. Turn all of the bypass air screws in fully.
c. Using the throttle body with the lowest vacuum
pressure as the standard, turn out the bypass
air screws of the other throttle bodies to
adjust them.
NOTE:
• Do not turn out the bypass air screw of the
throttle body with the lowest vacuum pressure.
• After each step, rev the engine two or three
times, each time for less than a second, and
check the synchronization again.
• If an air screw was removed, turn the screw 3/4
turn in and be sure to synchronize the throttle
body.
NOTE:
The difference in vacuum pressure between two
throttle bodies should not exceed 1.33 kPa (10
mmHg).

7. Stop the engine and remove the measuring
equipment.
8. Allow the engine to cool, and then start the
engine and check that the engine speed does
not rise abnormally high.
9. Adjust:
• Throttle cable free play
Refer to “ADJUSTING THE THROTTLE CABLE
FREE PLAY” on page 3-8.
10.Install:
• Caps
• Fuel tank
Refer to “FUEL TANK” on page 7-1.
• Rider seat
Refer to “GENERAL CHASSIS” on page 4-1.