Its the swept volume which is too high. Not too high in the sense of power for which it was originally devised but for flash over with oils. Its a little heat generator so don't put anything in it and clean out whats in it or your wasting your time.
As regard the finish, never wipe it over with lube...Alum is etched by petroleum's and silicones found in most oils.
It will slowly break the finish with patchy blotches over a period of a few years