Re: faster 9.8 hp
Well not too much you can do but.Eliminate as much weight as possible run with less gas if possible,distribute weight carefully.Be sure it has good compression and is in proper tune getting full throttle.You can also fine tune your setup.Be sure prop is in excellent shape.Anti vent plate should be about even with the bottom of the boat.You can try raising it 1/4 inch at a time until just before venting becomes a problem.Be sure it pumps water and clamp has a good grip.Adjust trim carefully.If one notch is not enough but next seems too much buy or make wedges so you can gain or lose 1/2 a notch.
Once your set up get a tach(tinytach) might work.Buy or borrow a gps and check your light load max rpm and speed give us the figures and prop size we can figure
if you can fiddle with the prop.
If you can gain a little from all these steps its not out of reason for you to gain 2 or 3 mph.
If you constantly run with a big load 2 or 3 guys and gear you may want to try a different prop but we will need those figures I talked about.
