I am new to power boating and had a question about trimming the
outdrive. The boat seems to get up on plane faster when trimmed all the
way down and the steering is good once up on plane. My problem is when
I try to trim up the boat wants to go left and it is a struggle to keep
the boat going in a straight line. I assume this is due to the rotation
of the prop and the fact that the outdrive is less efficient at steering
when it is raised slightly up. Is that correct ? What is the goal of
trimming? Should I trim up until the steering begins to get stiff
turning to the right??

Help !!!

Thanks in advance.

Dave wrote:
I am new to power boating and had a question about trimming the
outdrive. The boat seems to get up on plane faster when trimmed all the
way down and the steering is good once up on plane. My problem is when
I try to trim up the boat wants to go left and it is a struggle to keep
the boat going in a straight line. I assume this is due to the rotation
of the prop and the fact that the outdrive is less efficient at steering
when it is raised slightly up. Is that correct ? What is the goal of
trimming? Should I trim up until the steering begins to get stiff
turning to the right??

Help !!!

Thanks in advance.


The outdrive steering trim tab needs to be adjusted to offset the prop
wash & torque when trimmed out.

Your take-off technique is correct. Trim down for out-of-the-hole.

Running trim angle is to be adjusted up & out to maximize speed &
efficiency for a given engine RPM by getting the wetted surface of the
hull minimized, and the drive partially out of the water to reduce drag.
With the outdrive steering trim tab adjusted properly, steering should
be light & responsive on plane, & for the most part on-center. You are
trimmed out too far if the prop breaks loose or ventilates - too much of
the prop is out of the water and/or the trim angle exceeds the point of
diminishing return while trying to propel the boat forward.

This is the point where prop design & features beyond basic pitch(rake,
material, progression, diameter, blade shape & cupping) make the largest
gains or differences.

Rob