2-14 PERIODIC MAINTENANCE
IDLE SPEED
Inspect initially after 20 hours (1 month) and every 200
hours (12 months).
NOTE:
•
Before checking the idle speed, the engine should be allowed
to warm up.
•
Check and/or adjust the idle speed after the engine speed has
stabilized.
•
Before checking the idle speed, check the throttle link mecha-
nism and the throttle valve for smooth operation.
1. Start the engine and allow to warm up.
2. Attach the engine tachometer to the ignition high-tension cord.
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09900-26006: Engine tachometer
3. Check the engine speed.
Idle speed (in neutral gear): 650 – 750 r/min
ADJUSTMENT :
If the idle speed is out of the specification, perform the following
adjustment procedure.
4. Check that the CTP switch is in the ON position.
5. To set the IAC valve duty to constant 22.5%, raise the engine
speed to 1000 r/min or higher by turning the by-pass air screw
and hold that speed for 10 seconds.
At this time, the buzzer will sound to notify that the IAC duty
is in the fixed mode.
Turning air screw counterclockwise :
Engine speed will increase.
Turning air screw clockwise :
Engine speed will decrease.
NOTE:
•
While the IAC valve duty is at fixed 22.5%, the buzzer will sound
for repeated 0.5 second with an interval of 3 seconds.
•
The 22.5% fixed mode of the IAC valve duty will continue for 5
minutes and then it will be automatically cancelled.
6. During the fixed mode of the the IAC valve duty, adjust the
engine speed to 700 ± 50 r/min by turning the by-pass air
screw.