Mercury 80 hp max on starcraft 15 ft, 1970's ??

[Gomer50]

I am hoping someone can give me some insight on transom weight/max hp and buoyancy.On my boat sticker say's max hp 80.My 80hp 1972 weighs approx.250 lbs give or take a few with PTT now in the mid 60's Mercury made the inline 6 800 that weighs probably 300+ lbs. if I add PTT.Now If I were to put on a new motor lets say a 80hp 4 stroke it weigh even more. How much can a transom actually hold? How is this all fugured out? Besides the fact concerning liabilty issues and safety I have seen some 14ft - 15ft boats with huge motors on them. Wouldnt the boat sink or the transom give somehow? Ive also got a 90hp inline 6 that I want to hang off of a 1973 Marlin 15 footer tri hull thats only rated at 75hp and the transom is 1/2 thicker than my starcraft tri hull thats rated at 80hp.

 

[Chris1956]

Re: Mercury 80 hp max on starcraft 15 ft, 1970's ??

Gomer, Keep it simple. 80HP is 80 HP. If the displacement of the boat can take more weight, the four-stroker will work fine. On that 15 footer, walk to be stern and see how much more she settles into the water. If you and a friend can stand in the stern, the heavier motor is not an issue.
HP ratings are about the width of the hull and it's length. Bass boats are made real strong so that can take those large OBs.