The ornamental design for a generatorrunningcover, as shown and described.
FIG. 1 is a perspective view of a generator running cover showing my new design;
FIG. 2 is another perspective view thereof;
FIG. 3 is a front elevational view thereof;
FIG. 4 is a rear elevational view thereof;
FIG. 5 is a left side elevational view thereof;
FIG. 6 is a right side elevational view thereof;
FIG. 7 is a top plan view thereof; and,
FIG. 8 is a bottom plan view thereof.
The thick long even-spaced broken lines in the drawings depict stitching that form no part of the claimed design. The thin short broken lines in the drawings depict portions of the generator running cover that form no part of the claimed design.