The ornamental design for a four barrelcarburetor, substantially as shown and described.
FIG. 1 is a three-dimensional view of a four barrel carburetor showing my new design, looking upwardly at a first side thereof.
FIG. 2 is an elevational view of said first side; and,
FIG. 3 is an elevational view of a side of the carburetor that is opposite said first side.
The broken line showing of portions of a four barrel carburetor is included for the purpose of illustrating environmental structure and forms no part of the claimed design.