The shifter will only rev the engine when you push the button on the gear shiffter in. Sorry I am a new boater.mdpicard said:I have a 1988 3.0l mercury cruiser inboard outboard. The shifter will not put the boat in forward or reverse. It will how ever rev the engine. When I try to put it in gear the throttle and shifter cable start to bow. If any one has any ideas please help. Took lower unit off and gears seem to be working fine. Thank you for your help.