Repower

[smallies4evr]

I have a 1988 17' bluefin fish & ski. The 50 hp force just doesn't have enough umph! 22 mph with two people and 18 mph with our wives! And I'm the only large person (6'4"/250lbs) It runs great and has great/even compression. My boat is rated to 90 hp by the data plate. However using the USCG calculation formula, my boats size calculates out to 115 hp. Decent Outbords rated between 70-90 hp are hard to find in this area and I found a 100 hp outboard for a reasonable price. Is this a wise choice? My transom has been strengthened with a large aluminum plate and cap.

 

[Home Cookin']

Re: Repower

I have a 1988 17' Key West dual console--basically the same as a fish and ski. It came with a 70 and I have replaced that with a 70, and it's plenty of speed and power. I can't tell you my mph but I'd guess about 35.
One important reason not to go over the plate limit is so you don't void your insurance. 10 over may be perfectly safe, but that doesn't matter after an accident at any speed.

 

[Silvertip]

Re: Repower

Old HP or new HP, and boat size calculations do not alter the fact that your boat is rated for 90 HP. Depending on year, manufacturer and HP you may find that three different 90 HP engines all create very different sets of performance characteristics. One might get out of the hole faster than the other two but either of the other two may be faster and yet one of the three may be slightly more economical than the other two. Power the boat with the biggest displacement (cc) 90 HP and you won't be disappointed. See the "Boat Motors" button at the very top of this page? There are three 90 HP engines listed right here on iBoats (A Merc and two Yamahas).

 

[smallies4evr]

Re: Repower

Sorry HomeCookin and Silvertip, I had to step away from the computer for awhile. I understand what you both are saying. I can't see paying more for a new 90hp outboard that was more than what I paid for the boat. I have found used outboards in the HP rating I'm looking for, but by time you figure in shipping costs your at half of the cost of a new outboard and the ones I've seen are 20 years old or more. I just find it strange that I see boats the same size as mine, although fiberglass constructed and they have a higher HP rating than my boat. I'm thinking that the manufacturers keep things on the conservative side when it comes to rating boats for hp. For instance, I looked at a newer aluminum boat only 6" longer and 24" wider that was rated for 60 hp higher than my boat. Just strange to me. Thanks again

 

[Lion hunter]

Re: Repower

I would really look at your setup or boat weight. Granted a 90hp will be the best. But, I fish with a guy that has a 16 or 17' Spectrum that is probably almost the same as yours, his is powered by a 60hp Honda and will hit 32 loaded with 3 people.