Exceeding A Boats H.P. Rating ?

[charlie tuna]

I have a 14.7 G-3 Aluminum skiff, rated maximum H.P. is 15 H.P.. It has a 9.9 Four Stroke Merc on it now. With the gear i carry, fishing strickly inshore points and rivers, this engine is just enough to get up on a plane and "plane out" around 18 MPH. If i carry a second passanger, the performance just isn't there. I am considering moving up to a 15 H.P. Four Stroke Merc engine. Question: Should i exceed the boat's rating and go to a 20 H.P.? If i go to the 20 H.P., the dealer recommends electric start on the 20 H.P., and i have to factor that into the equation??? I am not looking for speed, where i fish, speed is dangerous. Just want enough H.P. to carry a second person and do what i do now?? Thanks For Reading.

[Flint River Pirate]

What's the width of that boat? I had an Alumacraft 1436 that I put a 20hp fourstroke Yamaha on and it was way too much. The transom was very close to the waterline.

[charlie tuna]

Width is 65 inches and the transon at centerline is 15 inches off the keel. Dealer recommends electric start if i go with a twenty H.P.. Say's the 20 H.P. will be too hard to pull?? The total weight difference between the 9.9 H.P. and the twenty is only 19 pounds. Thanks Again for the info.....

[charlie tuna]

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[crappielimits]

Insurance and coast guard regulations do not allow for over powering a boat. Sounds like you might want to consider lightening your load or going to a different hull. I had a 14 foot Lowe with a 15 hp and it would get away from you when just one man. I learned to add weight up front when I was by myself. It would run around 30 mph. I recommend a stick steer setup on these smaller Jon boat rigs. It is much safer and perfect for running rivers/creeks.

[crappielimits]

You also might want to check the compression, just in case you are not getting all from the 9.9 hp. It should push that size boat well if within weight regulations.

[charlie tuna]

The way the boat is outfitted - casting deck, trolling motor/battery,gear equates to an extra person, and like i said, it's performance with just me is fine -- about 18 MPH cruising. But i would like to have the ability to take a second person, and run about the same. Thats my intentions....

[Flint River Pirate]

18mph is about as fast as I would want to go in a 14 foot flat bottom boat.

[charlie tuna]

The hull is a "semi vee".

[Hiljun]

I have a 15 42 with a 25hp. I also have a whale tale and I have used multiple gps to get the speed and with just me no gear on calm water it will run 42. With me gear and 1 other 35 or so and with gear and three total 28 to 30. Now going down river while they are generating with gear and two people we can hit 45. I know the river I run very well or I would never go that fast. All that said to say I believe the whale tail makes a lot of difference. I know guys with the same boat and motor that just cant run that fast or plain as quick. When I come out of the canal I can be on plain in no time. Thats a lot cheaper than a new motor.

[CSMarine]

I understand the regulations with the Coast Guard and with the insurance companies, however there is one factor that I think both groups should concider with todays hp rating. A 14 foot boat made in the early 1980's may be rated for a 25hp motor. In the early 1980's that was fine, but today's 25hp motors are nothing like the ones made when the boat left the factory new. A 1980's 25hp Evinrude for example weighed about 115 pounds. They no longer make a two stroke 25hp Evinrudes, or any brand two stroke 25hp for that matter. So now you have to rig out with a four stroke motor, which weighes almost 200 pounds. Many small boats that worked fine with the two stroke just can't handle the weight of a four stroke, so the old weight allowence on the data plate is wrong. There's no way you can even meet the same hp rating,much less raise the hp to a larger motor, simply because of the weight.

[silverking]

Evinrude E-TEC 25-hp two-stroke fuel injected. Lightest version tips the scales at 146 pounds.

showroom_cat_engine_ETEC_25_INLINE.png (22.98 KiB) Viewed 4195 times

[Hit-n-Miss]

Try a Stingray Jr hydrofoil on your moter. I had one on a 25 with a 16' skiff. It would plane out with 2 people easy.

[Hit-n-Miss]

Mine was rated for a 40hp. $49.95 could fix your problem. Set your trim level with bottom of boat for 1st test. Then 1 notch up or down to tweak it.

[red_yakker]

I have a 20 hp pull start on my boat and it's not hard to start at all. Of course I don't have a mercury, I have a Honda, so it may be different. But the electric start is going to add weight to the motor, plus you'll have to add a cranking battery.