Metering Rod Adjustment
- Remove air horn and gasket. Hold throttle valve wide open. Push down on metering rod against spring tension. See Fig 1.
- Slide metering rod out of slot in holder and remove from main metering jet.
- Back out idle stop solenoid. Hold throttle valve in fully closed position.
- Press down on power piston. Swing metering rod holder over flat surface of bowl casting next to bore.
- Measure specified clearance between rod holder and carburetor surface. Measurement can be made using a drill or pin gauge.
- If adjustment is needed, gently bend holder arm up or down. Recheck clearance.
- Reassemble carburetor. Install new air horn-to-body gasket. Check for leaks.
Courtesy of GENERAL MOTORS COMPANY