Sure, the chain saw was not a weapon in Maniac Mansion, but in Bazooka Sue, the girl chops off every boner she sees (well not that way you think, just check the pic above).
In Lula 3d, in the locked kitchten, you can see (but not touch, grab or start) this version of a nice chain saw. Lula has a gun to fight back evil ...cardboard... skeletons.