The pin has nothing to do with your problem, as you said that it occurs even with high trim.
Your engine was probably removed from the transom by the repair man, end re-fitted in another vertical position, too low.
This kind of problem is very frequent, as all the engine installation manual insist to install the motor with the anti-cavitation (ventilation) plate set 2cm below the hull bottom.
This is good to get a very efficient trim action, but very bad for speed and water spray because the water bangs into the leg above the plate and is sprayed vertically - and possibly enters into the motor hood.
Solution : ask to have your engine raised in order to get this plate 2 to 3cm above the hull bottom line