1958 Mercury Accelerator Pump Stroke Adjustment
The Ford four-barrel carburetor will perform best when the accelerating pump lever is set in the specified hole. Nos. 1, 2, 3 and 4 designate the holes, starting with the one nearest the primary throttle shaft.
On carburetor EDG-9510-A used with the low-torque 383 cu. in. engine and automatic transmission, No. 2 should be used for summer operation and No. 3 hole for winter.
On carburetor EDG-9510-B used with the high-torque 383 cu. in. engine and automatic transmission, No. 3 hole is best for summer operation and No. 4 hole for winter.