Throttle Body Inspection; Cleaning; Iac Valve Replacement - Honda BF135A Manual

• Throttle Body Inspection/Cleaning
1) Remove the engine cover.
2) Remove the intake air silencer (P. 5-128).
3) Turn the throttle cam and check the throttle valve for
smooth movement and the throttle valve shaft for play.
4) Check that there is no gap between the throttle shaft
stopper and the throttle stop screw.
• The throttle stop screw cannot be adjusted. If it is
faulty, replace the throttle body.
THROTTLE STOP SCREW
THROTTLE BODY
5) Check the throttle valve and bore for contamination.
Clean if necessary.
NOTICE
• Do not spray the carburetor cleaner directly to the
throttle body.
• Use the genuine Honda carburetor cleaner.
• Do not wipe the throttle valve where is coated with
the molybdenum (i.e. both ends of the throttle valve).
6) Wipe the inner wall of the throttle bore and both ends
of the throttle valve with a shop towel or equivalent
material sprayed with the carburetor cleaner.
Coated with molybdenum
5-95
7) After cleaning, install the throttle rod and the silencer
chamber (P. 5-135).
8) After assembly, check the idle speed and adjust if nec-
essary (P. 5-94).

• IAC Valve Replacement

1) Remove the engine cover.
2) Turn the ignition switch OFF and disconnect the IAC
valve 2P connector.
3) Remove the two 8 x 45 mm flange bolts and remove
IAC VALVE
the IAC valve and IAC valve gasket.
IAC VALVE GASKET
3) Apply the engine oil to the new IAC valve gasket and
install it.
4) Install the IAC valve and tighten the 8 x 45 mm flange
bolts securely.
5) Connect the IAC valve 2P connector securely.
Clean.
6) Start the engine and let it warm up. Running the
engine at idling, check the IAC valve for proper opera-
tion (idle speed inspection; see P. 3-22).
BF135A•BF150A
2P CONNECTOR