The ornamental design for a portion of an exhausttip, as shown and described.
FIG. 1 is a front elevation view of a portion of an exhaust tip showing my new design;
FIG. 2 is left side elevation view thereof;
FIG. 3 is a perspective view thereof;
FIG. 4 is a reduced side elevation view thereof; automobile,
FIG. 5 is a reduced side elevation view thereof; shown in use on an automobile; and,
FIG. 6 is a reduced side elevation view thereof. shown in use on a motorcycle.
The broken line showing of portions of the exhaust tip and motor vehicles are for illustrative purposes only forms no part of the claimed design. The broken line adjacent to the shaded area represents the boundary between the claimed design and the non-claimed areas and forms no part of the claimed design.