motor too big??

[coon commander]

hi all. i have a 1986 17.5 ft hrdrasport with a 140hp johnson on it. i found a really good deal on a 91 225 hp johnson and was wondering if that was to big? i looked up the specs and its around 100 lbs heavier maybe a lil less. i dont know bout this stuff just asking. didnt know about it coming out of the hole or when letting off of it water coming over the back? or if its just too heavy to begin with. thanks for any help

 

[Sunsetrider]

Re: motor to big??

Re: motor to big??

The plate on the transom should set out the max hp for the boat. If you exceed it the result is very unpleasant. Don't ask how I know!

 

[LippCJ7]

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Re: motor to big??

ABSOLUTELY NOT!! You can never have a motor that is too big, but your boat could be too small........

 

[Fireman431]

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I've owned 3 20' boats. All three had a max of a 175 on the plate. You wanna put a 225 on the back of a 17.5' boat? You're asking for trouble.

 

[riptorn]

Re: motor to big??

Re: motor to big??

You'll be jumping across the water like a dolphin and taking in water on sharp turns and possible fined by the coastguard depending where you are. I had a boat that was 25hp over rated and it was terrible on the water. 100 + pounds is too much weight on the very back of that boat.
Just my opinion from past experience.

 

[coon commander]

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it doesn't say any limit on the boat or transom or i woulddnt have asked. i'm not the first owner so it could have been taken off

 

[Bob_VT]

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That hull is ONLY rated at 140 HP max

If you want a 225 then you need a boat rated for it. The 225 will either kill you or the boat but death would be involved.

 

[docster]

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Re: motor to big??

not complete truth here. I wont get into it here to avoid controversy. But head on over to screamandfly.com/forum.php we will help you out with it.

 

[docster]

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Re: motor to big??

oh no worries. we will do just that haha. But simply put, to say ,no you cant isnt true. you can do it safely, now driving it safely, thats entirely on him, but we can build it safe.

 

[NYBo]

Re: motor to big??

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I hope there are some naval architects/engineers on that board. It's not just hull integrity that's at issue. The speed at which a particular hull remains safe is a big factor to be considered.

 

[Philster]

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On Scream and Fly, a 225 HP engine could be found on a 13' boat. Good times.

 

[docster]

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On Scream and Fly, a 225 HP engine could be found on a 13' boat. Good times.

maybe even 2! haha.

 

[riptorn]

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I would love to see this fly across my lake on a windy day. LOL

 

[Ike-110722]

Re: motor to big??

Re: motor to big??

Well I hope those folks at screamandfly never encounter a state boating law enforcement officer.

First I am retired Coast Guard who spent 25 of my 34 years working in Boating Safety. Nuff said about that.
The federal law applies to boat manufacturers. Simpy put, it says they must put a label on monohull outboard powered boats under 20 feet in length stating the maximum safe recommended horsepower. It says nothing about boat owners or operators, or an owner putting an engine on the boat that is larger. So you will not be cited by the USCG for overpowering.

Also most boat manufacturers, regardless of type of boat, follow the standards of the American Boat And Yacht Council. They have a horsepower standard for all types of boats with engines. These are the standards used in court by plaintiffs attorneys and state law enforcement prosecutors. They are the standards that the court relies on. So if the standard says 140 HP, the lawyers or the judge will ask you, why did you exceed 140 HP? I wanted to go fast, is not a good answer.

Now the caveats:
1. If you are operating the boat in a negligent or grossly negligent manner (because of that big motor) you can be cited by the Coast Guard, state or local authorities for negligent or grossly negligent operation. This carries hefty fines. Some state authorities can cite you directly for overpowering, see #4.

2. The amount of flotation in your boat is based on the weight of the boat, the weight of the people and the weight of the outboard. You chunk another hundred pounds back there and the boat will no longer float level if it will float at all.

3. The horsepower of the boat is based on a standard formula developed by the boating industry many years ago. The formula was derived by testing many boats through a safe maneuvering course. They kept putting bigger engines on and running the boat through the course until the boat got squirrely. Then they used the last HP where it wasn't squirrely. All this data was used to determine the formula for how much HP was safe on different types of boats. There is a different formula for different types of boats.

4. Now for the one that will get you in court: Many states have passed laws that make it a violation to exceed the values on the label. I know of numerous people who have been cited by state or local law enforcement specifically for exceeding the rated maximum capacities.

5. And here's the one that will cost you the most. If that boat is insured (liability insurance) and you have an accident where people are hurt, and your insurance company discovers the boat was overpowered, they will deny your claim. You will be personally liable for paying any damages or medical costs for the injured parties, and you will be open to a lawsuit. The insurance company will not assist
you. You will end up not only paying the above, but all the court costs and lawyers fees.

Last but not least by any means. When a naval architect or small craft designer, designs a boat they calculate what would be the most efficient horsepower for that boat. A lot of things are taken in to account to get to horsepower. The weight of the boat, the boats center of gravity, center of resistance on the bottom, amount of resistance, how much vee the boat has, what trim angle the boat will run at, how the boat will trim when standing still, how much of a load the boat will carry, and so on. I can assure you hanging an additional 100 lbs on the transom will definitely change the boats attitude when standing still, as well as when underway. If the boat was not designed to carry that much horsepower it will definitely act differently than with the lower hp. And how many more mphs will you gain, not to mention how much more fuel you will use to achieve that speed?

So to put it mildly, it's not a good idea.

 

[H20Rat]

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Re: motor to big??

Also most boat manufacturers, regardless of type of boat, follow the standards of the American Boat And Yacht Council. They have a horsepower standard for all types of boats with engines. These are the standards used in court by plaintiffs attorneys and state law enforcement prosecutors. They are the standards that the court relies on. So if the standard says 140 HP, the lawyers or the judge will ask you, why did you exceed 140 HP? I wanted to go fast, is not a good answer.

As far as the court issue, I"d be curious to know if there is a single case EVER of engine size affecting the outcome of a trial as you indicate...

I don't get it, with boats people get all worried the instant someone is 10 hp over the 'limit', but yet the same guy saying this is horrible will tow his 15' tinny to the lake with a diesel with a power tuner, putting out double the factory rated horsepower and torque. Wait, why doesn't that apply then? If he is driving too fast and t-bones someone, the added horsepower is never an issue. The fact he was an idiot and didn't know how to drive is.

(yes, I'm ignoring the weight difference, but its also possible to add power without adding weight. Obviously a 225 2 stroke stroke is going to be a heavy beast, but a 4 stroke 140 is no lightweight either.)


(and the last disclaimer... I've driven LOTS of high performance vehicles. Some on land, some on water, and even was lucky enough to get my hands on one in the air. Every single one of them had a working throttle, and every single one of them could kill you the instant you quit respecting the throttle. My point is, you don't need to use 100% of the horsepower all the time.)

 

[mommicked]

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Peter, that reply was awesome. Very well said.

 

[riptorn]

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Your right in most ways smokingcrater, you can have a 300hp on the back of your boat but once you compromise the weight balance of the boat it makes it dangerous to the people on the boat and fellow boaters also. I owned one that was over balanced with a heavy over rated motor on the back. Not fun to drive towing skiers on the back and a endowed wife sitting beside me cursing and swearing lol.

 

[Home Cookin']

Re: motor to big??

Re: motor to big??

It's all about context. Drag racer cars do not have street legal equipment, but there are restrictions on where and how they can be operated. And dirt bikes, ATV's, etc. Even a golf cart can be "illegal" on the wrong road. And so, there are street cars, street legal bikes, etc.
When someone asks on iboats about rigging a boat, the safe assumption is that he's talking about a general recreational boat used in public open water. On screamandfly, it's about racing boats. Simply different use, different context.

As for legal issues: first, as Peter said, it's how it's operated that matters more than how it's rigged, except in a few places where they codify the safety ratings. In that regard, it's just like cars: mine can go 100 but that doesn't make it uninsurable or illegal to drive--as long as it's under the limit. second, as smokingcrater mentions, you have to understand the legal concept of "proximate cause." If you are idling your overpowered boat and run over a kayaker, the fact that it was overpowered, as for insurance coverage or liability, is irrelevant. Same as my 100 mph car in a 15 mph wreck. But if you are overpowered, running WOT lose control and flip, then it's a safe bet that your overpowering was the proximate cause of the wreck and down you go from there.

That's the basics; there are some tricky admiralty laws that can change things, as well as some insurance clauses. A recreational boater shouldn't take the chances; a racing hobbyist needs to know the risks.

 

[Ike-110722]

Re: motor to big??

Re: motor to big??

As far as the court issue, I"d be curious to know if there is a single case EVER of engine size affecting the outcome of a trial as you indicate...

Well, my disclaimer. Since I retired in 2004 I no longer have access to the USCG files. If I did, yes I could cite cases where horsepower was the issue. However, I received many calls and letters over the years from boat owners who had been cited by state or local law enforcement for exceeding the values on the label, as well as for not having a label. The Coast Guard's official position was (and still is as of a year ago, because I asked) is that the states have that authority. I also talked to many insurance adjusters over the years about this issue.

You are right that the control is on the throttle, but it is also my experience with over 55 years of boating that boaters (particularly power boaters) know only two speeds, stopped and 3/4 or more throttle. Unless they are fishing you rarely see anyone just cruising along at just a little over planing speed. I have dealt with all facets of the boating community from canoes, kayaks, sail boaters to Unlimited Hydroplanes. The go fast crowd is just that. (I was a member of the Hot Boat Forum until the went bankrupt) They like to go fast. That's fine with me as long as they do it where they aren't endangering anyone but themselves, and not breaking any laws. I think some of those boats are really cool. But I have also investigated several hundred boating accidents over 25 years, some involving very fast boats designed to go fast, that got into trouble for whatever reason, and some one got killed. So you can understand my reticence about hanging 225 Horse on a small boat designed for 140.

 

[riptorn]

Re: motor to big??

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I agree Peter Eikenberry. I sat my butt in an unorthodox boat I bought, your more worried about dumping it than having fun. Especially when your trying to pull up a skier with your nose pointed straight up for a 1000 yards to plain out and the prop cultivating and I don't know what is in front of me because I have too much weight on the back end. But once I plain out, man it goes. All over the the place.
It's nice to play around but you have to be practical about having a safe vessel.
It wasn't much faster for the trouble than the recommended hp.