So Pilot boats had the titles 520, 570 and 590, is yours the 590?
Many years ago I had a Pilot 520 with a 50hp outboard. The only issue we had was that somehow water got into the areas under the floor. Never found out how it got in there but our solution was to fit drain plugs and periodically let it out. Had great fun on that boat as no doubt you will have with this one