Yamaha 2009 YZF-R1Y, Service Manual

Page: 373 / 526

THROTTLE BODIES
7-16
Before cleaning the throttle bodies, check the
following items:
• Valve clearance
• Spark plugs
• Air filter element
• Throttle body joints
• Fuel hoses
• Air induction system
• Exhaust system
• Breather hoses
WARNING
EWA14B1021
• If the throttle bodies are subjected to
strong shocks or dropped during clean-
ing, replace them as a set.
• Before removing the throttle bodies to
clean them, check the operation of the
throttle bodies, refer to “FUEL INJECTION
SYSTEM” on page 8-33.
1. Check:
• Throttle bodies
Cracks/damage
→
Replace the throttle
bodies as a set.
TIP
If the protector “a” is scratched or damaged,
replace the throttle bodies as a set.
2. Clean:
• Throttle bodies
ECA14B1027
• Observe the following precautions; other-
wise, the throttle bodies may not operate
properly.
• Do not open the throttle valves quickly.
• Do not subject the throttle bodies to
excessive force.
• Wash the throttle bodies in a petroleum-
based solvent.
• Do not use any caustic carburetor clean-
ing solution.
• Do not apply cleaning solvent directly to
any plastic parts, sensors, or seals.
• Do not directly push the throttle valves to
open them.
• Do not touch the bypass air screw “a”
with a white paint mark; otherwise, the
throttle body synchronization will be
affected.
▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼
a. Place the throttle bodies on a flat surface
with the air filter case side facing up.
b. Install the caps (895-14169-00) onto the
hose fittings “a”.
c. Push the lever in the direction shown in the
illustration to hold the throttle valves in the
open position.
WARNING
EWA14B1022
When cleaning the throttle bodies, be care-
ful not to injure yourself on the throttle
valves or other components of the throttle
bodies.
ECA14B1028
Do not open the throttle valves by supply-
ing electrical power to the throttle bodies.