Mercury - Gen I Throttle and Shift Cable 24 Foot Mechanical Engine Control 8M0082497. The Mercury Gen I Throttle and Shift Cable (24 Foot / 7.3 m) is designed for boats using traditional Mercury Gen I mechanical control systems where extra routing length is required. This cable connects the control box to the engine to deliver direct, responsive throttle and shift movement without electronic involvement. The 24-foot length is ideal for wide-beam boats, deeper hulls, and extended console layouts