Motor hp rating for boat

[jacobcraft7]

I have a 14x48 flat bottom ouachita 1971 and I'm looking at getting an evinrude 25 etec. Motor weights 146 lbs.i don't see the plate on the boat that says the rating. Any help is appreciated.

 

[Willyclay]

Re: Motor hp rating for boat

The link below will get you to the current USCG regs for manufacturers and then you can follow the appropriate formula for your boat. Exceeding the calculated maximum horsepower rating potentially puts you at risk for some liability in the event of an accident. Be safe!

http://www.gpo.gov/fdsys/pkg/CFR-2004-title33-vol2/pdf/CFR-2004-title33-vol2-sec183-53.pdf

 

[arks]

Re: Motor hp rating for boat

My Lowe 1448 'BigJon' is rated for 25HP max. I run a 2 stroke 25 'Rude with no issues.
I'd think the etec would weigh significantly more than mine, however.

 

[Willyclay]

Re: Motor hp rating for boat

A 14ft long by 4ft wide transom width boat with remote steering AND at least a 20 inch high transom would calculate exactly 25HP maximum by the USCG formula; i.e. 14X4=56X2=112-90=22+3=25. A boat of the same dimensions without remote steering OR less than a 20inch transom would have a maximum horsepower rating of only 15HP; i.e. 14X4=56X0.5=28-15=13+2=15.

 

[roscoe]

Re: Motor hp rating for boat

CG formula is not set in steel.

My 14' x 36" jon is rated for 20.
I'm sure your boat can handle a 25 if the transom is solid.

Prudent use is probably more important. Put a 15 on there and I bet I can still get into trouble and fill her with water.

THe etec only weighs about 20# more than a 25 hp conventional 2 stroke.

 

[steelespike]

Re: Motor hp rating for boat

The dry weight of your boat may help.
Todays 14/48 jons of about 230 lb dry weight and above will usually be rated for 25 hp.
If your old-timer is closer to 180 it will be for a 15 or 20 hp.

 

[jacobcraft7]

Re: Motor hp rating for boat

My transom is pretty solid. It has flat bar braces that look pretty beefy. It had a 35 hp on it b4. Can y'all see the picture in my original post?

 

[steelespike]

Re: Motor hp rating for boat

I see the straps.What do you think the boat weighs? If its 230 you and a buddy could lift it fairly easily.
If you weigh the bow and then the stern on your bathroom scale it should be close
to the actual weight.Try to get the weight centered on the scale.You may have to prop the bow up with a 2 X 4
to get it centered.You'll have to keep the boat level so it doesn't drag unevenly on the scale.

 

[jacobcraft7]

Re: Motor hp rating for boat

I see the straps.What do you think the boat weighs? If its 230 you and a buddy could lift it fairly easily.
If you weigh the bow and then the stern on your bathroom scale it should be close
to the actual weight.Try to get the weight centered on the scale.You may have to prop the bow up with a 2 X 4
to get it centered.You'll have to keep the boat level so it doesn't drag unevenly on the scale.

Hmmm that seems difficult lol. I might try and do that tonight. The boat isn't thin but I wouldn't say it's thick either. I've seen much thinner in old jon boats

 

[Home Cookin']

Re: Motor hp rating for boat

To help you justify buying that 15 for Christmas, an underpowered boat can be dangerous, especially in winter time use like duck hunting. You need to be able to beat it home against wind waves and current, and not only is more power better for the obvious pushing, you have better control with more speed/power than at the max of an underpowered boat. More power helps you stay dry and outrun following waves/chop.

I've never considered top speed in MPH relevant to my boating, but power is essential.

 

[steelespike]

Re: Motor hp rating for boat

I've never done this but I would prop up the bow as close to the front as possible weigh the stern and level it firm at a good height.
to weigh the bow close to the spot you propped it. Don't worry about the weight of a 2 X 4 if you need it on the scale.

 

[jacobcraft7]

Re: Motor hp rating for boat

I got the 25 etec and I love it. It's is perfect. Plane out almost instantly out the hole and top at 28 mph

 

[Willyclay]

Re: Motor hp rating for boat

Congratulations! Hope you enjoy that great motor for many years. Thanks for letting us know what you decided.

 

[boobie]

Re: Motor hp rating for boat

You made the right decision. They are a good motor. I'll take them over any 4 stroke any day. Keep in mind, less moving parts to break.

 

[steelespike]

Re: Motor hp rating for boat

A great motor.No service for 3 years or 300 hours,no break in period.
fewer and less complicated service intervals.

 

[jacobcraft7]

Re: Motor hp rating for boat


I was very pleased. It cranks on the first pull every time. Not too loud and not too much motor like I thought it would be. Cost me a good bit but it'll pay off when I'm gettin somewhere in a hurry

 

[steelespike]

Re: Motor hp rating for boat

Looks great,thanks for the picture.How about a video on the water?
I bet she just about jumps out of the water.
There is a Etec test of a 16 ft utility w a 25 does 31 mph w 2 aboard at 6000 w a 12" prop.
gets 16 mpg at 21 mph.

 

[jacobcraft7]

Re: Motor hp rating for boat

Looks great,thanks for the picture.How about a video on the water?
I bet she just about jumps out of the water.
There is a Etec test of a 16 ft utility w a 25 does 31 mph w 2 aboard at 6000 w a 12" prop.
gets 16 mpg at 21 mph.

Maybe i need to adjunto the trim.went 25 with my buddy and by myself I hit 28. Me +the motor + the boat I'd say that's close to 500 pounds. I have a video let me are if I can upload it

 

[jacobcraft7]

Re: Motor hp rating for boat

 

[steelespike]

Re: Motor hp rating for boat

It's hard to tell but it looks like the motor may be a little low. Usually suggested for the antiventplate(just above the prop)to be even with or slightly above the bottom. You should be able to raise it about an inch without any modification just by putting a stick on the transom to hold up the motor while you tighten the clamps.
Typically a 15" motor will actually measure about 17".Some boats will allow the antiventplate to be up to an inch above the bottom.
I usually suggest raising the motor to a point just before ventilation becomes a problem.
Is your prop a 12" pitch? Have you tried trimming up a notch?
Most jon boats will get up on the water pretty easy but sometimes have 4 or 5 keels that may cause drag.
Yours may have a lot of rivets adding to the drag as well.
28 is by no means slow but that 30 mph barrier may be obtainable.