Re: Cannot trim motor up - Porpoising
OK, there's a couple of things to look at. First, are you sure the diameter is 13 3/4 rather than 13 1/4?
Now, if you move 50 lbs from the stern to the bow, in an equal distance from the fulcrum point, you are actually making a 100 lb shift in balance. IE - making the stern 50 lbs lighter and making the bow 50 lbs heavier. If you move the 50 lbs further forward of the balance point than it was behind, you'll actually make a shift of more than 100 lbs. Not as far forward, less than 100. If you move 50 lbs from the stern to exactly the fulcrum, you've lightened the stern by 50 lbs but added nothing to the bow weight. Obviously, none of these moves effect the total weight.
Is the motor mounted all the way down on the transom? We assume it's bolted to the transom with no jackplate or set back, right?
Lets look at this stuff and then maybe look into some Smart Tabs.