Checking And Cleaning The Throttle Bodies - Yamaha VMAX 2009 Service Manual

Pressure drops → Properly install or replace
the injector
L LLL L LLL L L LLL L
EAS2S31095
CHECKING AND CLEANING THE THROTTLE
BODIES
TIP
Clean the throttle bodies only if they cannot be
synchronized using the bypass air screws. Be-
fore cleaning the throttle bodies, check the fol-
lowing items:
• Valve clearance
• Spark plugs
• Air filter element
• Throttle body joints
• Fuel hoses
• Air induction system
• Exhaust system
• Breather hoses
EWA2S31033
WARNING
• If the throttle bodies are subjected to
strong shocks or dropped during cleaning,
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 bod-
ies as a set.
TIP
If the protector "a" is scratched or damaged, re-
place the throttle bodies as a set.
a
2. Clean:
• Throttle bodies
L LLL L L LLL L L LLL L
ECA2S31068
NOTICE
• Observe the following precautions; other-
LLL
wise, the throttle bodies may not operate
properly.
• Do not open the throttle valves quickly.
• Do not subject the throttle bodies to exces-
sive force.
• Wash the throttle bodies in a petroleum-
based solvent.
• Do not use any caustic carburetor cleaning
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 portion "a" of the throttle
valve shaft; otherwise, the throttle body
synchronization will be affected.
M MMM M MMM M
a. Place the throttle bodies on a flat surface with
the engine side facing up.
b. Install the caps (18P-2464V-00) onto the
hose fittings "a".
a
c. Fit a suitable pipe "1" (D = 11 mm, d = 9 mm,
and L = 140 mm or more) onto the projection
"a" on the throttle valve shaft, rotate the shaft
in the direction shown in the illustration to
hold the throttle valves in the open position.
7-14
THROTTLE BODIES
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a
a
M MMM M MMM
a
a