I have a 1970 DuraNautic 12 foot aluminum boat (for now) that has an '82 Johnson 9.9 on it that runs great. However, with full load of fuel, kid, tackle, rods, small cooler, can't get boat on plane. The plate on the transom says the boat will take up to 12 hp outboard and honestly, I can't remember ever seeing a 12. So, was thinking of throwing on a 15hp outboard.
The question is...was 10 or 12 hp back in 1970 rated differently than in the 80's or 90's, or even in the 2000's with 4-strokes? Was a 10-12hp back in 1970 stronger or weaker than my '82 9.9hp or a 9.9 form the 90's.
Can I put a newer 15hp on the boat without tearing it apart or should I reinforce the transom somewhere?
I just saw an ad for a 1974 18hp Evinrude at a great price...but think it might be too powerful and too heavy so am still thiking 15hp instead. Many of the Johnson/Evinrudes of the 80's...the 9.9 and 15's were almost identical with minor differences like carbs throat sizes and exhaust ports.
The question is...was 10 or 12 hp back in 1970 rated differently than in the 80's or 90's, or even in the 2000's with 4-strokes? Was a 10-12hp back in 1970 stronger or weaker than my '82 9.9hp or a 9.9 form the 90's.
Can I put a newer 15hp on the boat without tearing it apart or should I reinforce the transom somewhere?
I just saw an ad for a 1974 18hp Evinrude at a great price...but think it might be too powerful and too heavy so am still thiking 15hp instead. Many of the Johnson/Evinrudes of the 80's...the 9.9 and 15's were almost identical with minor differences like carbs throat sizes and exhaust ports.