Bayliner Speed Boats

it has a force of 120 Mercury outboard and the boat weighs 1600 lbs.

Your top speed at WOT (full throttle) should be specified in your manual.
Take the boat on a calm day with a lot of Running Room and PEG throttle.
You are looking for two things a) the ability of engine to WOT and b) speed.

Assuming you can reach WOT, gradually trim the engine began to lift the bow ... done slowly and carefully .. that the boat up versions, the speed should increase ... when the bow began to "porpoise" aka bounce up and down, then cut down a little bit until the boat is stable .. what is your max speed of your boat / engine combination.

oh, measure the speed with a GPS .. your speedo lies.

This is about average for a boat that the weight of an engine of this size. You should get about 5000 - 5500 rpm at WOT. Plus you need a higher degree of the proposal, not least, a lower pitch of course. Also, after mounting the engine too low on the table will have an impact on performance. All the weight in the boat that is not necessary, it is slow you down and increase fuel consumption too.