transom, shaft length question

[matt194]

How much lower should my motor hang compared to the bottom of the boat? Also I have a 1975 14.5' skiflite tri-hull with a 1979 115hp Evinrude on it. The paper work I have from new mexico said the max horse is 85hp but on iboats it says 70 hp. Am I way over the max horsepower to where I will cause harm to myself or others?

Thanks,

Matt

 

[oops!]

Re: transom, shaft length question

the anti cav plate is paralell with the bottom of the hull.......

as far as hp rating.......its here

http://files.dnr.state.mn.us/education_safety/safety/boatwater/backyardboatbuilders.pdf

do the calculations of safe powering


cheers
oops

 

[matt194]

Re: transom, shaft length question

What is the anti cav?

 

[Chris1956]

Re: transom, shaft length question

Matt, Oops means the Anti-Ventilation plate. The A-V plate is the horizontal plate on the lower unit, above the prop. It is wide enough to get about 1/2 your foot onto on each side. That should be level with the bottom of the boat hull, or slightly above the boat hull.

BTW - a 115HP motor on a 14.5' boat sounds extremely dangerous to me.

 

[oops!]

Re: transom, shaft length question

thank you chris

i also didnt see 14.5....

is this scream and fly?

 

[tashasdaddy]

Re: transom, shaft length question

you are overpowered, there can be legal problems if and incident occurs. also if stopped my water cops, and they notice, they can red tag, your boat. you do not have to use all that hp, but imho, i would power it correctly.

 

[matt194]

Re: transom, shaft length question

Thanks for all the help. I am going to try and find a 70-80hp.

 

[oops!]

Re: transom, shaft length question

that rudes worth a few dollars....you should come out ahead on this one