Adjusting The Throttle Body Synchronization - Yamaha YZF-R1(B) 2012 Service Manual

4. Install:
• Vacuum gauge "1"
• Digital tachometer
(Use goods on the market)
Vacuum gauge
90890-03094
Carburetor synchronizer
YU-44456
5. Install:
• Air filter case
Refer to "AIR FILTER CASE" on page 7-
5.
• Fuel tank
Refer to "FUEL TANK" on page 7-1.
6. Check:
• Throttle body synchronization
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a. Start the engine, warm it up for several
minutes, and then let it run at the specified
engine idling speed.
Engine idling speed
1150–1250 r/min
b. Check the vacuum pressure.
The difference in vacuum pres-
sure between the throttle bod-
ies should not exceed 1.33 kPa
(10 mmHg).
If out of specification → Adjust the throttle
body synchronization.
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PERIODIC MAINTENANCE

Adjusting the throttle body synchronization

1. Adjust:
• Throttle body synchronization
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a. Start the engine, warm it up for several
minutes, and then let it run at the specified
engine idling speed.
Engine idling speed
1150–1250 r/min
b. There is a white paint mark on one of the
throttle body's bypass air screw "1".
Use the throttle body as the base to syn-
chronize the other throttle bodies by turning
their bypass air screw in or out.
ECA14B1039
Do not turns the bypass air screw at the
throttle body which is the base for synchro-
nizing; otherwise, the engine may run
roughly at idle and the throttle bodies may
not operate properly.
TIP
• After each step, rev the engine two or three
times, each time for less than a second, and
check the synchronization again.
• If a bypass air screw was removed, turn in
the screw fully and be sure to synchronize
the throttle bodies.
• If the throttle body synchronization can not
adjusted by the bypass air screw, clean or
replace the throttle bodies.
• The difference in vacuum pressure between
the throttle bodies should not exceed 1.33
kPa (10 mmHg).
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2. Stop the engine and remove the measuring
equipment.
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