I have a 13 foot dory (flat bottomed speedboat) with a 35hp mercury 2 stroke outboard engine.?

Question

The boat sits up on the plane at about half throtttle, however at 3/4 to full throttle the boat tends to dip at the bow causing a lot of spray. Would changing the angle of the prop up or down help or does anyone have any other ideas. This happens when the weight is evenly distributed.

Answer 1

You are on the right track. You have to trim the motor i.e. alter the shaft angle. Trial and error is the only way. If the bow lifts a little too much after increasing the angle between the shaft and stern you may find it easier just to move some weight towards the bow.

Answer 2

There's a "thrust rod" (yes that's really what it's called -- get your mind out the gutter!) stuck through a pair of holes near the bottom of the bracket, that the motor is resting against.

There are several more sets of holes that allow you to set the "trim angle" by moving the thrust rod out or in.  Take it out a couple holes.

Answer 3

i have a dory too, but have a two horse on it, so dont have this problem myself! My guess is keep the weight to the stern, and perhaps change the angle of the engine, this should helps, good luck!