I have a 1974 15hp Evinrude that I really like, I use it with my 1969 MkI Zodiac. I used to have a 25hp Evinrude (1980 something) on my 12.5 foot Polaris RIB and liked it but the boat could have used more power with more than two people in it (rated to 50 or 60hp). Is there any reason that I shouldn't go with a similar older style 2 stroke Evinrude in a 35hp on my new 1979 MkII Zodiac? Would a 25hp be better or a larger motor? The boat is rated to 55hp but I would like to beach launch so 150lbs or so would be the max weight that I'd like to haul around for a motor but at the same time I would like to be able to get on plane with up to 800lbs in it.