I have a fiberglass 12' trihull skimapp. I have an 87 johnson 6hp that weighs 55lbs. and want to upgrade to a 2009 tohatsu 9.8 four stroke that weighs 85lbs. how much of an increase in speed should i see the 6 hp was somewhat unreliable and am thinking of making this purchase with income tax in mid march. The hull id has 10hp max but I am installing a new transom and seats, so the transom definately has the beef.
