I had my 1988 75 horse Mariner carbs cleaned and floats adjusted. I also had the fuel pump parts replaced. Before I had the work done It would run at 5100 rpm at wot. Now it tops out at 4600. He adjusted the timing and throttle lever and idle screws. It also surges and drops at wot. He told me to put new plugs in it to see if that fixes the problem. what I want to know is if the throttle lever screw is in too far would that affect my top end. In other words if the the top arm stops too much before the bottom would that keep it from topping out at what it should be?