User Manual

23
Adjustment
NOTE: Engines may have a fixed idle or limiter cap on
the idle fuel adjusting screw. Step 2 can only be
performed within the limits allowed by the cap.
1. Start the engine and run at half throttle for five to 10
minutes to warm up. The engine must be warm
before performing steps 2 and 3.
2. Low Idle Fuel Screw Setting: Place the throttle
into the “idle” or “slow” position. Turn the low idle
fuel mixture screw out (counterclockwise) from the
preliminary setting until engine speed decreases
(rich). Note the position of the screw. Now turn the
mixture screw in (clockwise). The engine speed
may increase, then it will decrease as the screw is
turned in (lean). Note the position of the screw. Set
the adjusting screw midway between the rich and
lean settings. See Figure 16.
3. Low Idle Speed Setting: Place the throttle control
into the “idle” or “slow” position. Set the low idle
speed to 1500 RPM* (± 75 RPM) by turning the low
idle speed adjusting screw in or out. Check the
speed using a tachometer.
Figure 16
NOTE: To ensure best results when setting the low
idle fuel Screw, the low idle speed must not exceed
1500 RPM* (± 75 RPM).
Lean
Rich
Adjust to Midpoint