maximum hp rating

[gator-24]

I have a 1989 spectrum 1700 fish ski boat i can't find the maximum tag..and i am wondering what maximum horse power i can go up to..it has a 70 horse now..and i think it is to small for the boat..by my self i can get about 28 miles an hour..but anymore weight it drops way down..please help

 

[snapperbait]

Re: maximum hp rating

Hi Gator.. If you can't get the info, here is a web site that has the formula to figure the max HP for your boat...<br /> http://www.herknperk.com/HTMLobj-1743/USCGPamphlet.pdf

 

[Solittle]

Re: maximum hp rating

gator - You can pound through the formulas (which you should probably do anyway) or go buy a 110-130 hp motor which should give you plenty of performance. Any of the 4 cylinder models. A V6 would be a screamer but my guess would be too heavy and most likely be way over what the formula would yield.

 

[roscoe]

Re: maximum hp rating

I have a Spectrum 16' SC and it is rated for 75hp.<br />The new Fisher 16'sc is rated at 60hp. <br />These 2 boats are almost identical, weighing about 730 lbs.<br />The Fisher 17'Hawk sc is rated for 150hp, it weighs 1400 lbs.<br /><br />Like SoLittle said, 90 to 115hp is probably ok, but best to do the calculations, or try to find more info about the original rating plate. You may be able to contact Brunswich or Fisher.

 

[gator-24]

Re: maximum hp rating

does anybody know what size prop i should be running..it has a 15 pitch prop on it now..and does the diameter of the prop matter..ive been thinking about dropping down a couple of pitches..thanks

 

[Boatin Bob]

Re: maximum hp rating

Do you have a tach? You should know what RPM you are running at WOT and see if thats in the right range for your motor first. If you go and drop a couple of inches in pitch your RPM's are going to go up roughly 200 rpm per inch of pitch, this will do nothing for your top end speed, in fact you will lose some but on the other hand your hole shot will improve but the important thing is to make sure your WOT RPM is within the specs.

 

[petryshyn]

Re: maximum hp rating

that old merc is rated at the flywheel for HP. You've got about 50 at the prop....