throttle cable...adjustable?

Are our cables adjustable? (Guessing from body lift) My cable has like 1.5" of slack in it. I have to push the pedal down a bit before it moves, and it never 'fully opens.' I have an aftermarket TB, so I'm not sure the last little bit of movement really matters. (I would say the plate is about 1/5" from hitting stopper).

As a tempory fix, I kind of rigged a washer on the pedal itself that pulls the cable out the small gap, but I would rather adjust it if possible. It doesn't look like it, but figured I would double check.