I had same type of problem one time and it was the screen in the pick up tube in the gas tank getting **** in it when quite the **** fell to bottom allowing it to start and run untill it got cloged i took screen out put in inline filter run perfect after that
Only thing with them lunds is the transom is so low not good for big waves my buddy had a starweld with that ****y low back and 3 fters were coming over the back allmost sunk really scary
I don’t no for sure but im pretty sure that is just a aluminum piece over plywood a guy i no thought he had a aluminum floor in his sea nymph and was just a plate over the plywood