Overpowering your boat.

petriw

Seaman Apprentice
Joined
Aug 29, 2005
Messages
44
I wasn't sure where to put this. If I am out of line someone please tell me. I have a 1989 15 1/2 foot, bow to propeller, FiberTech Glass boat with an 1989 80 horse Merc. triple on it. It is dangerously fast. I am sure it didn't start out with that size of motor. I am relatively new to boating, this is my second one, so I am a little dumb and quite cautious yet. Maybe I bit off more than I can chew.
It does seem heavy in the stern to me. Fully loaded with 4 adults the transom drains are taking a little water. Once underway that stops. It planes quite quickly and nicely but I get a lot of torque steer prior to that.

How much power is too much power? Am I too heavy? What can I do?


S.O.G.F.W.B.
slow old guy with fast boat.
 

EricR

Petty Officer 1st Class
Joined
May 17, 2007
Messages
296
Re: Overpowering your boat.

If it's an '89, she should have a factory rating plate somewhere.
 

Silvertip

Supreme Mariner
Joined
Sep 22, 2003
Messages
28,758
Re: Overpowering your boat.

Four people on a 15 footer is a fair load so it will make the little bugger squat. Look for the capacity plate which is generally located somewhere inside the boat -- usually on one side panel or the other. The maximum rated HP will be indicated on that plate.
 

petriw

Seaman Apprentice
Joined
Aug 29, 2005
Messages
44
Re: Overpowering your boat.

It says 48 kilowatts. Whatever the hell that is.
 

bassboy1

Lieutenant Commander
Joined
Jun 23, 2006
Messages
1,884
Re: Overpowering your boat.

To give you some perspective. My 15 foot deep vee is rated for 80 horse, and 6 people.
 

bassboy1

Lieutenant Commander
Joined
Jun 23, 2006
Messages
1,884
Re: Overpowering your boat.

Wup, we posted simultaneously. Where does it say 48 kilowatts? That does not have anything to do with outboard ratings or weight ratings. I don't think that you are looking on the right plate.
 

studlymandingo

Commander
Joined
Mar 22, 2006
Messages
2,716
Re: Overpowering your boat.

It is dangerously fast.

Fully loaded with 4 adults the transom drains are taking a little water. Once underway that stops. It planes quite quickly and nicely but I get a lot of torque steer prior to that.

Define "dangerously fast" I have yet to achieve this.

It is normal for deck drains to take on water if you don't have scuppers. I would recommend the ball-type as they close pretty well.

Torque-steer is normal for a boat with only single-cable steering; you can counter this to a degree by adjusting the torque-tab anode just above the prop. Using a no-feedback steering setup or hydraulic steering is the only way to completely rid yourself of the torque-steer.

80 doesn't seem too far out of range for a boat that size, as long as you aren't chine-walking severly, you can just keep the throttle where you feel comfortable. If you happen to be boating in my neck of the woods, look me up I would love to experience "dangerously fast"!!!:D
 

petriw

Seaman Apprentice
Joined
Aug 29, 2005
Messages
44
Re: Overpowering your boat.

Ball type drains sound interesting. Where could I get ball-type drains? My little boat with just me in it does about 51 mph with a moderate wind at the stern.
 

petriw

Seaman Apprentice
Joined
Aug 29, 2005
Messages
44
Re: Overpowering your boat.

Thank Shamus2. That confirms I am overpowered. 64 vs 80hp.That is almost 20%. I suppose there are plenty of people that wouldn't care but there is a a significant weight difference between engines in those 2 categories. About 100 to 150 pounds. That's a lot of extra weight on my skinny *** little transom that wasn't meant to be there. Causes me some concern.
 

BigNiner19

Petty Officer 1st Class
Joined
Jul 1, 2006
Messages
234
Re: Overpowering your boat.

i bet it dont have a problem getting up on plane. I got a 15' ft boat with a 60 hp johnson and my boat FLY'S. My boat is probably a little lighter than yours though.

Cory
 

roscoe

Supreme Mariner
Joined
Oct 30, 2002
Messages
21,657
Re: Overpowering your boat.

He said 15', bow to PROP !!
So the boat is only 13.5 feet long. ! ?


Tiny boat, too much power.

That being said, if it isn't illegal to overpower in Canada, then use it.

You don't have to go full throttle, 3/4 throttle is just fine.
 

Texasmark

Supreme Mariner
Joined
Dec 20, 2005
Messages
14,544
Re: Overpowering your boat.

Hey, slow old guy with a fast boat. Check out my Avatar. That's a 50 mph wake and I'm over 65. Grin.

Between that and my new SWB, 2 dr.,Dodge Hemi P/U in Candy Apple Red, 20" chrome spokes and all, I feel like I'm 18 again.

Just hang on tight...........but I'm legal. Actually my boat is rated for 130 and I only have a 90 on it. Hmmmmmmm

Mark
 

petriw

Seaman Apprentice
Joined
Aug 29, 2005
Messages
44
Re: Overpowering your boat.

You are only as old as you behave.
 

idominate5

Recruit
Joined
Sep 26, 2010
Messages
1
Re: Overpowering your boat.

I have a 18.5 foot bass boat with a 100hp moter on it that i just bought.
and its rating plate is all scratched out. it has two aditional meatal plates for stranth. but i want to put a 200hp on it. should i or should i not
 

NYBo

Admiral
Joined
Oct 23, 2008
Messages
7,107
Re: Overpowering your boat.

I have a 18.5 foot bass boat with a 100hp moter on it that i just bought.
and its rating plate is all scratched out. it has two aditional meatal plates for stranth. but i want to put a 200hp on it. should i or should i not
Welcome to iboats!:cool:

Rather than adding on to an ancient thread, you should have started your own. But since you asked...

What year, brand, and model is the boat? There is more to power rating than what the transom has the strength to hold. I would guess that your boat is probably rated for 150 if it is older, but it could be more if it's a newer model.
 
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