Throttle Valve (Basic Setting)

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, it is not used to adjust idle speed.

Throttle Valve Adjusting Screw:

1. To correct a faulty Throttle Valve adjustment, loosen the locknut and use a screwdriver to back off the throttle valve adjusting screw until there is clearence between its tip and the throttle valve lever. 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 and turn the screw in an additional 1/2 turn and tighten the locknut.

2. Check the vacuum hose fittings at the throttle valve for proper vacuum signal as some fittings can become plugged, this is due to the introduction of PCV vapors near the throttle valve. If signs of PCV residue are found, remove the intake air hose and visually check the throttle valve. Clean the vacuum fittings and throttle valve with spray type carb-cleaner as needed.