I have a 74 SeaStar with a 74 Mercury 1150 outboard. The control unit for shifting and accelerating is not correct. When I first bought the boat and put in forward and pushed the control further forward it gave it gas and the boat accelerated nicely. Now I have to push both the idler lever and the control lever all the way forward to get the boat going. Where is the adjustment for this. Is it at the motor or in the control unit? Thanks for your help. David