Motor Size

[mudcatwilly]

I am considering buying an aluminum jon boat and then buying a used motor separately.  Let's say I get a 14 or 15-foot boat.  What do you think is the largest motor that I can put on a boat that size.  I want maximum power, but I want the thing to be stable.  I have an opportunity to buy an envinrude 90hp, but I think that will be too heavy.  Can I at least get away with a 50hp motor?

[Guest JoshKeller]

I'd say a 9.9 or a 25 hp would be max.  You can also get the 90 hp, and resell it or trade it.

[Low_Budget_Hooker]

All depends which boat you end up with.  There is a manufacturers tag on every boat.  Has max hp printed right on it

[Grey Wolf]

My Lowes 1448 has a motor rating of 25 horse I believe.

[ThomasL]

A site for all

www.uscg.mil/d8/mso/louisville/WebStuff/comdtpubp16761_3b.pdf

site to figure hp ratings

[timmyswetarded]

put a couple wings on that thing if your going to put a 90hp on that lil guy .....i think thats a little over powered....i have a 16' v-hull and 25hp pushes it around pretty good...i mean sure i'd love to have a 35 or 40 on it but it might be illegal....and not safe

[flechero]

My 15' modified V was rated for 25hp.  Every boat will have a coast guard plate mounted inside with max HP, persons and weight.

[timmyswetarded]

actually a lot of older boats dont have those plates....i know mine doesnt...its a 1972 i think...but yeah all the newer ones do

[flechero]

actually a lot of older boats dont have those plates....i know mine doesnt...its a 1972 i think...but yeah all the newer ones do

I bet it had one when it was new.  Many of those older models had mounted to the transom board... when the transoms are replaced the plates don't always go back on.   Mine was a 71' and I helped restore several 60's model Lone Stars all of which had a plate on the transom also.  All of them that we remembered where we put the plate during restoration, got put on the new transom... 2 didn't. ...lol

[flechero]

A google follow up to my post and I found this:

In response to a mandate from Congress contained in the Federal Safe Boating Act of 1972 (FSBA), the United States Coast Guard issued regulations covering small outboard boats and the maximum rated horsepower for them. The regulations bind the manufacturer to provide a capacity plate that shows the maximum rated horsepower for each hull.

The applicable regulations can be found in 33CFR183.53 The manufacturer must state the horsepower as no more than that computed under the formula, except, if the manufacturer conducts the performance testing procedure, the results of that testing can be used (with some qualifiers). However, the manufacturer is apparently free to state a lower rating if desired, and sometimes does. Note that the regulations only require ratings for monohull boats under 20-feet in length.

In another section it stated that before 1972 it was not mandatory and some manufacturers did not supply a capacity plate.

[timmyswetarded]

ohhh ok well ill check around do some research to see if alumacraft put them on their boats in 1972 thanks for the help

[burleytog]

My 78 Fisher has one of those plates, but it has long since faded out.  One would think they would make them a little more durable.  :-/