You need to move the entire grip assy back (to the center line of the bike).
The grips expand slightly when heated and are rubbing, let me guess, on your throttle lock?
Loosen the grip assy, and move it back on the bar 1/16 or less of an inch. That will give the grip room to expands when hot and not rub.
"Integrity, justice, courage, and action - without these, a person is of no consequence." Don Nelson my friend gone from us, 06/06/04.