Throttle Valve Basic Adjustment

The purpose of the throttle valve adjusting screw is to provide a positive stop and prevent the valve from closing so far that it becomes worn or damaged.

To correct a faulty throttle valve adjustment, use a screwdriver to back off the throttle valve adjusting screw until there is clearance between its tip and the throttle valve lever. The adjusting screw is shown in Fig. 5-2. Place a thin piece of paper between the throttle valve adjusting screw and the throttle valve lever. With the throttle valve closed, turn the screw in until it lightly contacts the paper. From this position, remove the paper and turn the screw in an additional 1/2 turn.

Fig. 5-2.

Location of adjusting screw (arrow) for throttle valve basic adjustment (not used to adjust idle speed).