This is a 4.3 Volvo Penta by the way, 190 hp.

This is my first boat with trim adjustment. I have been trying to
maximize speed according to the speedo w/o adjusting the throttle. So
you are saying ignore speedo and try to get the rpm up?

Can anyone explain in simple terms what the theory is behind trim
adjustment. I start off with the engine all the way down, right? Then
when I get onto a plane I raise it a bit? How much to raise it is the
mystery for me! Conditions on our small lake are usually fairly calm,
load is usually about 2 or 3 adults = 400 pounds.

Many thanks for all responses!


Eisboch wrote:
"James" wrote in message
ink.net...
Merc?

There is a sending unit in the side of the outdrive. Where the outdrive
pivots up and down. One side is the sending unit, the other side is the
trim limit switch. Both commonly have those wires break off and/or get
corroded.


And, they are also difficult to fix. Might be better to learn to trim by
"ear" anyway because different conditions and loads require different trim
settings. With practice the OP will learn to recognize the "sweet spot".
Try slowly trimming out for maximum engine RPM without adjusting the
throttle.

Eisboch