I replaced the shift lever remote control in my remote control (the plastic detents had cracked-original equipment). When I got it back together, it started fine, went into foward fine, but won't go into reverse. It seems like the shift lever or shifter won't go far enough back. Before I did the replacement, I disconnected the shift cable and manually checked the gears. All, forward-neutral-reverse, were okay. I'm new to shade-tree mechanic work on boats. Any ideas???