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Author Topic:   50hp on 13' whaler?
Romano69 posted 12-04-2000 09:04 PM ET (US)   Profile for Romano69   Send Email to Romano69  
I resently bought a 84' 13' whaler with no engine.I was wondering if anyone has an idea on how fast this boat would go with a brandnew 50hp Johnson.I'll run it with a 17 to 19 pitch prop,just me and the 6 gallon gas tank.Any Ideas?
dscew posted 12-04-2000 11:01 PM ET (US)     Profile for dscew    
Your 13 will be a rocket instead of a boat if it gets a 50 HP engine, at least out of the hole. Wheelies on the water, anyone? The 13 is rated for a 40 HP maximum, and may lose stability with that much power (a 25% increase over the 40). It may also be stern heavy, pulling the bow up too high and compounding the safety issues of overpowering. For safety's sake, I hope you'll stay within the rated HP. Just my opinion...
Romano69 posted 12-04-2000 11:39 PM ET (US)     Profile for Romano69  Send Email to Romano69     
The 40hp and 50hp Johnsons are the same engines.The diffrence is in the carberator. But i do think it will move really fast. This one guy said if i get the right prop i can pull off at the most 50mph or reaching close to that.I wonder if that true?
lhg posted 12-05-2000 12:32 AM ET (US)     Profile for lhg    
I ran a 1958 13 Sport with a Merc in-line 4 50Hp (powerhead rated in those days) for a couple of years. The boat will handle the HP and weight, but gets a little squirrely around top speed of 45-47MPH. If you do this, raise the engine one bolt hole and run a performance prop, which will help stability. You might want to consider a 6" setback jack plate, which will allow you to "fine tune" engine running height and boat stability. (The higher the height, the more stability you get) But I'd take previous advice and stay with a modern day 40HP if I were you. There will be few times when you can use the full 50 horses.
lhg posted 12-05-2000 12:35 AM ET (US)     Profile for lhg    
ps: There is a lot of other information on engines for a 13 buried in this site. Seek it out by expanding the time frames for various threads.
Clark Roberts posted 12-05-2000 06:50 AM ET (US)     Profile for Clark Roberts  Send Email to Clark Roberts     
Romano, I ran a 13 with a Pro 50 yamaha for awhile and about 44 was top speed. A friend has a Johnson 48 spl on his 13 and he gets about the same... to get this speed you have to pass through a speed range where extreme instability occurs as the 13 hull has a "terminal velocity" of about 36 mph above which it becomes unstable.. The hull will literally dance side to side and only extreme trim will keep the bow from digging in.... Be safe and careful... and remember that if you're involved in some sort of accicent, even if not your fault, you are likely to be held liable.... not my place to give you advice, just some thoughts 'cause I've been there! Happy Whalin... clark
Romano69 posted 12-05-2000 03:21 PM ET (US)     Profile for Romano69  Send Email to Romano69     
Thanks for the opinons.I think ill still go with the 50hp.If the handling comes to query then ill let off the trottle until it gets comfortable.I just like the idea that i have the extra horsepower when i need it.Does any one have anymore ideas on how to make the boat more stable.I like the idea with the 6inch setback but wouldnt that put stress on the transom.-Thanks
bigz posted 12-05-2000 03:51 PM ET (US)     Profile for bigz    
Frankly your idea of using a 50hp is way off in never never land --- one reason you will never need or can effectively use 50hp on a 13 period! In fact you really don't need even 40hp -- just because something says this is max or maybe "cool" isn't necessarily where your going to achieve the best performance --- like the saying goes "fools and their money" -- my 2 cents -- bigZ
DIVE 1 posted 12-05-2000 07:02 PM ET (US)     Profile for DIVE 1    
A 13 with a 50 is a blast on calm days. LHG makes a good point, a setback jackplate definately is the way to go. If you can handle the expense, buy a lightweight hydraulic unit and install a water pressure gauge for the engine. Lift the engine underway until the water pressure decreases slightly, then lower the engine down a little to regain full water pressure. Keep an eye on the tach at the same time, being careful not to exceed the WOT rating. This is a trial and error process. You will also have to play with different props. We solved the instability problem with some small fixed trim tabs. As the speed increases the wetted surface decreases and leads to instability. With the trim tabs, the wetted surface is extended further back and stability increases.
Good Luck,
(can't have enough speed)Jim
compounder posted 12-05-2000 07:32 PM ET (US)     Profile for compounder  Send Email to compounder     
Romano I have already made the mistake you are about to. I owned a 13 for over 20 years and had 3 engines on it---a 25, a 50, and a 40. The 25 was entirely satisfactory but I thought just like you do that the extra power would be nice if I needed it. Well, I never really needed it. The boat was too stern heavy. The "prop torque" made the boat lean far to starboard when accelerating hard. And, worst of all, I finally managed to flip the boat over. I goosed it in the middle of a hard turn and the next thing I knew I was in the water. The new 50 came with new controls, which for the first time gave me an emergency kill switch, so the boat was shut off and floating ahead of me upside down. The next day I traded the 50 in on a Mariner 4 cyl. 40 which was still a little too much power for the 13. I would think a 30 or 35 would be about right for the 13. Do what you want, it's a free country, for the most part. I'm not a lawyer, but I believe if you have an accident and someone or someone's property is injured you will be stuck with "contributory negligence" as will the dealer or individual who rigs the boat for you. Hate to sound so negative, but I thought you might benefit from my experience.
dscew posted 12-05-2000 08:51 PM ET (US)     Profile for dscew    
I have to agree with Compounder. I used to sell Whalers in a previous life, and at our dealership we wouldn't think of hanging an overrated engine on any boat. No dealer with any sense will do this. I also have a friend who flipped his overpowered boat while accelerating, and nearly drowned under it. His next move was to re-rig within the guidelines. Again, my 2 cents, I hope you do the right thing.
Romano69 posted 12-05-2000 11:39 PM ET (US)     Profile for Romano69  Send Email to Romano69     
Again,thanks for the opinons.First off compounder,the 50hp mariner you had was a over 250lbs 4cyl engine.I would never put something like that on my 13'boat.The Johnson 50hp is a 190lb 2cyl which is the same as the 40hp Johnson which is rated for this boat.As i said before i wouldnt open the trottle full if the boat was feeling query.The times i would open it full is when im carrying people,pulling wakeboarders-tubes or when i feel its calm enough to open the trottle with just me aboard if the boat is handling well.I like the idea with the trim tabs but im still not sure about the jackplate.I wouldnt want to much stress on the transom.Anymore comments or ideas on how to make this boat more stable?Where do i get fixed trim tabs from?-Thanks
compounder posted 12-06-2000 02:39 PM ET (US)     Profile for compounder  Send Email to compounder     
My 50 was a Yamaha 3 cyl. Weight listed as 189 lb.
Also, I recently took a ride in a neighbors 13, powered by a 30 hp Tohatsu. He said the Tohatsu 30 only weights about 105 lb. Power was good and the rig was well-balanced with 2 adults on board.
andygere posted 12-06-2000 03:02 PM ET (US)     Profile for andygere  Send Email to andygere     
I ran a '72 13 with an '86 2 cyl. 40 hp Merc for many years, and the boat was plenty fast. I would not want less than 40 hp if you are planning on having more than one passenger, and plan on carrying 2 gas tanks, fishing gear etc. The 13 is a marginal ski boat even with the 40 hp, not due to power, but because a strong skier will move the boat around quite a bit. It is a bit unnerving for the driver, and I could see it getting you into trouble. At the same time, I would not put more than 40 hp on a 13 for the same reasons listed above. I used to borrow a similar 13 with a Merc 50, and it was really squirrelly at WOT. I think the 40 hp is the best choice if you carry any loads in the boat. Lower hp is probably fine if you tend to go solo.
Romano69 posted 12-06-2000 08:04 PM ET (US)     Profile for Romano69  Send Email to Romano69     
Today i say the most overpowered 13' whaler ever!It was a 13' Whaler with a 70HP Johnson!!I wanted to ask the guy how it ran but he was to far out(I was at the beach).When he took off it didnt look like he was at full trottle but it was still going fast ill say a little over 40mph and it looked very stable with the bow slightly up and one person in the front.I didnt see anything special like a jackplate.In my opinon thats a waste of a 70hp engine.I would put it on a 15 or 17' whaler.Ill keep you all posted if i get to talk to him.
DIVE 1 posted 12-06-2000 08:22 PM ET (US)     Profile for DIVE 1    
We made our own fixed trim tabs from .090 thick stainless steel. Start out with a piece 6"wide x 8" long, make a 90 degree bend in the plate, leaving 1 section 6" x 6" and the other section(that attaches to the transom) 2" x 6". Trial and error time. Run the boat and note the ride angle. If you need to change the angle, you can bend the plates(by hand) either way to achieve the desired angle. NOTE: when you initially put the plates on the boat, lay a straightedge on the bottom of the hull and bend the plates so they are parallel with the hull.
I remember fixed trim tabs for sale some years ago, I think they were plastic. I haven't seen any lately except on some older wooden boats
FISHNFF posted 12-07-2000 01:02 AM ET (US)     Profile for FISHNFF  Send Email to FISHNFF     
I ran a 1981 13' Whaker with a 35 Evinrude and was never satisied with the power. In '89 I bought a 40 Yamaha and was very pleased. Power trim does wonders on any size boat. I recalled part was not properly fixed by the dealer, causing a blown powerhead, so I paid for the upgrade parts (reed valves, exhaust manifold, and carb jets) to make it a factory 50(cowling and serial # still a 40). Noticed a little more speed (40.2 knots on GPS) pulling 5600RPM with a 15"SS prop. Engine growled more and was more torquey. To get max speed you had to trim out and it did get squirelly. Trimming down for a smooth ride brought speed down to about 34 knots. But this was never meant to be a speed racer. Do not exceed max for legal reasons!
russellbailey posted 12-07-2000 09:17 PM ET (US)     Profile for russellbailey  Send Email to russellbailey     
Several persons on this list mention the possibility of being cited for "negligence" if you have an accident and have a motor over the rated hp.

Does anyone actually have an example where this happened? My impression is that this is like the bogeyman, an oft repeated possibility, yet not realistic, told to sway people to stay inside the lines.

Further, if someone was actually cited for negligence, would the person have been cited for it anyway based on reckless handling? Or was it actually based on the hp being over an industry recommendation?

Note that we have a 70 hp on a 15', which is the rated power. Since we mainly ski, I would not go for any less power. If we could have gotten a more powerful engine at the same weight, we'd have done it.

For the question posed by Romano69, I would say definitely get the 50 if you waterski a lot IF it has more low and mid range power. Even our 70 works hard pulling an adult up on one ski. As long as you drive it responsibly, I am very skeptical of any realistic liability you would face.

Just my $0.02, like everyone else.

Romano69 posted 12-08-2000 04:03 PM ET (US)     Profile for Romano69  Send Email to Romano69     
Here in the US Virgin Islands you would not be held responsible if your boat was in a accident and the boat was overpowered.But thats due to the layed back island vibes.I dount no how it works on the mainland.
I am getting the 50hp Johnson for my 13' whaler as soon as i get a little more money in my "boating account".Its costing me $3728 due to a 5% discount for paying in cash.The boat will be used as a recreation boat for pulling wakeboarder,skiers,tubes and when im going island hopping i need it to carry at least 5 people. It will not be used as a race boat as many people on this forum may be thinking.-Romano69-

PS-Thanks for seeing it my way russel-

Clark Roberts posted 12-08-2000 10:05 PM ET (US)     Profile for Clark Roberts  Send Email to Clark Roberts     
Russell, I believe that Compounder and I were the only ones who mentioned the liabiliy aspect and as for me, I'd like to make it clear that I don't tell "bogeyman" stories and I surely don't try to keep anyone "inside the lines"....!!!! I don't see how you could read that into our comments!! Happy Whalin'... Clark... The Old Man and the Sea
bigz posted 12-09-2000 09:15 AM ET (US)     Profile for bigz    

Think you might check out your statement with the

U.S. VIRGIN ISLANDS Dept. of Planning &Natural Resources
396-1 Annas Retreat, Foster Plaza
St. Thomas VI 00802

There is no penalty or fine associated in current Federal boating regulations with regard to over loading or over powering based on the USCG or manufactures capacity plate, however quite a few states and territories have these areas covered in their laws and one could be cited for this violation, always best to check your local boating laws.

As far as liability more or less it would be up to the party or parties involved in any accident on just what they want to nail the at fault person/boat for which could mean if it is an accident that stems form control and/or speed then an over powered craft is highly likely to be suspect.

That said like Clark mentioned it is your choice of how you power your boat --- no one here is telling you what to do --- you asked for advice and you got it --- maybe some of which you didn't want to hear ---

Have fun, be safe and enjoy your boat --- BigZ

Romano69 posted 12-09-2000 10:55 AM ET (US)     Profile for Romano69  Send Email to Romano69     
Thanks for the address,I think ill give them a call pretty soon.Where did u get it from?
I do appreciate all the comments made on this forum and i took each on into consideration.I now no what i am going to do with my boat.-Thanks- ~Romano69~
lhg posted 12-09-2000 06:22 PM ET (US)     Profile for lhg    
Regarding this overpowering issue: As an Insurance Broker/Agent who sells marine insurance, and seeing a woman who is lawyer, and as an owner of 4 overpowered Boston Whalers at various times, maybe I can shed some light on the issue.

First of all, make no mistake about it, Insurance Companies do not like overpowered boats, especially if this results in high capable speeds of over 50 mph. But they can be insured, with certain companies, usually with a higher rate class, if the operator has a good DRIVING record, is middle aged, and no prior history of boating claims. The fact that the boat is a Boston Whaler also helps. Whalers are kind of considered the Buick Park Avenues of boating. I have my two overpowered Whalers insured at about a 50% premium increase, even though I've never had a claim. So there is a price to pay.

As has been indicated, when you're above the rated HP, you, or your insurance company, is certainly more vulnerable to CERTAIN types of liability claims. So greatly increased care must be exercised during operation, particularly accelleration or top end operation. An at fault accident at high speed will hang you. If there's any way an attorney can establish that the higher horsepower might have contributed to the accident, you're going to suffer. If not, there is probably no reason for HP limit to be relevent. If you're idling through a no wake zone and go over a swimmer, HP is not the issue. But if you're going 60 and go over a swimmer, they will claim the boat was out of control and recklessly operated, partially because of excess HP. Then you've got a problem, and so could the Dealer that set you up. That's why they're so afraid of the situation, a situation they have no control over (how you operate a boat). So my best guess would be that if or when a liability claim arises when the EXTRA HP (over rated HP) is being used, you've got a problem. This could apply to either accelleration OR top speed. I suppose extra weight/balance could also be a contributing problem, but the advent of the heavier clean engines could negate some of this. Even a jack plate, or jacked up engine could be a problem, within rated HP, as these devices have a reputation as "hop up" situations to increase a boat's speed.

I know that I rarely use the extra horsepower for either accelleration or speed, and am a careful operator, using the power mostly for extra load carrying and increased engine life reasons. So I am not as concerned about the liability situation. And I carry a lot of insurance. But if speed is your primary agenda, you should be concerned. Injury to your own waterskier with an overpowered boat could also be a problem if they sue. Remember you are just as liable to your own passengers as you are to other boaters.

bigz posted 12-11-2000 03:17 PM ET (US)     Profile for bigz    

I got that info for the islands from a brochure I think we picked up about 5 years ago in St John -- guess it is still the right phone #.

Might want to take a look at these semi-fixed trim tabs --- also can be used as a step

ADJUSTABLE STEP-N-TRIM the small size would be just about right for a 13 --

Larry makes some very good points on insurance over powering possible problems -- I would guess your carrying insurance!


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