Checking The Throttle Body Joints; Adjusting The Throttle Body Synchronization - Yamaha FZ8NA Service Manual

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.
▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲

Adjusting the throttle body synchronization

1. Adjust:
• Throttle body synchronization
▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼
a. With throttle body #3 "1" as standard,
adjust throttle bodies #1 "3", #2 "2", and #4
"4" using the air screws "5".
ECA14900
Do not use the throttle valve adjusting
screws to adjust the throttle body synchro-
nization.
TIP
• After each step, rev the engine two or three
times, each time for less than a second, and
check the synchronization again.
PERIODIC MAINTENANCE
• 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).
▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲
2. Measure:
• Engine idling speed
Out of specification → Adjust.
Make sure that the vacuum pressure is
within specification.
3. Stop the engine and remove the measuring
equipment.
4. Install:
• Synchronizing hoses
5. Adjust:
• Throttle cable free play
Refer to "ADJUSTING THE THROTTLE
CABLE FREE PLAY" on page 3-30.
Throttle cable free play
3.0–5.0 mm (0.12–0.20 in)
6. Install:
• Fuel tank
Refer to "FUEL TANK" on page 7-1.
• Inner panel/side panel/front cowling side
panel (FZ8SA)
Refer to "GENERAL CHASSIS" on page
4-1.
• Rider seat
Refer to "GENERAL CHASSIS" on page
4-1.
EAS21010

CHECKING THE THROTTLE BODY JOINTS

1. Remove:
• Throttle bodies
Refer to "THROTTLE BODIES" on page
7-5.
2. Check:
• Throttle body joints "1"
Cracks/damage → Replace.
3-10