An injector for delivering liquid can include a body having a proximal end, a distal end, a longitudinal axis, and a track follower adjacent to the proximal end. A plunger can be disposed at least partially within the body and movable with respect to the body along the longitudinal axis. An actuator can be positioned at the proximal end of the body and operably connected to the plunger. The actuator can include a track having a first portion and a second portion. The first portion can limit travel of the actuator along the longitudinal axis to deliver a first predetermined amount of the liquid. The second portion can limit travel of the actuator along the longitudinal axis to deliver a second predetermined amount of the liquid. The actuator can be positionable to selectively control displacement of the plunger pursuant to the first portion or the second portion of the track.
