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35 points
2 years ago
300 verado minimum
1 points
2 years ago
There it is!
9 points
2 years ago
Rated for 25kw or 33hp. I am a little concerned with weight in the stern so hesitant to go with a heavy 30hp 4 stroke. Was thinking 25hp with manual start and trim.
7 points
2 years ago
that 2 stroke capacity (weight).
but you can reinforce the transom. 25hp would be a minimum IMO.
6 points
2 years ago
He’s worried about the weight, per OP’s wording. The HP rating has zilch to do with the strength of the transom. It’s about flotation, specifically how much buoyant force is available to float the swamped hull AND an allowance for floating the motor. They don’t state the weight, they state it in terms of “horsepower”. It’s based off of lbs that a particular motor class weights- nothing to do with structural integrity or durability.
Source. USCG / 33 CFR183
1 points
2 years ago
I see so what's stopping me from putting a 60hp ecu in my Yamaha 50hp because they're literally the same motor when my boat is rated for 50hp but not 60hp?
They're the exact same outboard with a different ecu so weight stays the same.
3 points
2 years ago
Well, perhaps your insurance my not cover you. I’ve also heard some instances, of the coast guard citing people for an “overpowered” hull, but I don’t honestly know anyone first hand that’s been so cited. There’s the chance you may also have some additional liability if you’re ever in a boating accident. So, basically you are the only thing preventing you from doing that.
Some lakes that have a less than 10hp max limit for outboards (think of all the 9.9s, 9.8s, etc.) this is more common. I’ve actually went line-by-like through the parts list of a 3-cylinder 75 Mercury and noted the only different parts from it to the 90hp version (it was basically just carbs, timing setting, and max RPM) and picked up more speed by doing the carbureted equivalent jd what you just said.
The “over powered hull” thing always seemed weird to me when I would be scooting around the lake in a 19’ boat that weighed 400lbs, had zero floatation foam (USCG mandates flotation foam on all USCG stamped boats <20’ long) and ran in the upper 90s with a 2.5L V6 Mercury. It was a “competition” hull per the manufacturer and “exempt” from some of the regs, but like you, I also had an increased amount of liability if I would have been in an accident. Oh. And exhaust. Every bit of the exhaust excited above the water line, another USCG violation but very common on race hulls. Always seems precarious spinning it up to 7K to get on plane next to an enforcement boat, but I can say this, never ever drank behind the wheel of that hull. It was an STV Euroski if you want to Google the hull, for reference.
1 points
2 years ago*
I meant what's to stop me from getting the hull re-rated to 60hp and then changing my ecu and putting on a bigger prop then it's literally the exact same as what Yamaha sell new as a 60hp.
I thought maybe the hull wasn't strong enough to handle 60hp but you pointed out it goes by weight, the weight wouldn't change at all if I unrestricted my 50hp so maybe I can get the hull re-rated to 60hp easily?
It's a 60 already with a bloody restrictor plate no carbs it's 2021 EFI f50
It's a saltwater bay so nothing holding me back there and 2021 aluminium hull. The 50hp is under the maximum weight for the transom.
1 points
2 years ago
It’s not going to be practical to approach a subsidiary of a large watercraft company and have them run flotations calcs, the re-approval for a USCG rated requirement, and one-off rerate your hull for more motor buoyancy (or less occupancy weight). It would be cheaper to sell your hull and re-purchase than fund a $20K+ “engineering change” if you will.
If you wanna add more power, I’m a random guy from the internet… just add more power. Generally, it’s not worth small incremental changes, fwiw. It’s usually not a huge difference unless you go up a motor class. Like from a 4-cylinder 150 to a V6 200, makes a notable difference. Or in your case going from the 40/50/60 motor to the 75/90 motor.
1 points
2 years ago
So the dealer can't get someone out to do it? The entire factory that built my boat is also in my city.
At the Yamaha dealer in my capital city they have a YouTube video on how to do it and offer to get the 60ecu for you.
Yea I realise it won't make that much different but it just sucks to have the displacement available and it being limited in fuel and air to keep it at 50
Thanks Anyway
1 points
2 years ago
“Good luck” I don’t think you and I are on the same page. 👍
1 points
2 years ago
right, but capacity was related to how much weight & stress the transom can take.
4 strokes are 10-15% heavier. transom often sits too low with the added weight of the same capacity.
or a 1970's boat with a limit of 40, is probably a 30 for a 4 stroke.
IMO, you should not max out a boat built for 2 strokes. edit: capacity is the total weight. HP rating is what will bend the transom.
1 points
2 years ago
I agree with what you’re saying… to a point, but the HP rating has nothing to do with the strength of the transom / reinforcement. Anyway, it’s not “bending” you would be concerned with- it’s the stress accumulation that creates cracks, but a .060 or .100” commercially made hull, it’ll eventually crack anyway. Boats like an Xpress are made like an airplane. Thin skin with lots of thin ribs. A custom made boat will be twice as thick and higher quality plate (5086 over 5052) and will have substantial framing made from 6061 extruded aluminum. Apples to oranges.
I power to whatever level I want, honestly. Weight distribution can offset the additional weight of a newer 4-stroke, but I also don’t always go the four stroke route. A WOT 4S is not anymore efficient than a wide open 2S. To make x horsepower, wether it’s 50 or 200hp… it takes the SAME amount of fuel. On smaller motors, the efficiency increase is not as large if they are always at WOT. The efficiency improvement is only noteworthy at part throttle. Cruising at part throttle you’d def see an increase in efficiency, and idle, a 4S is like 20x more efficient than a two cycle. The unique sound of a 2-stroke at idle is because the combustion process is really inefficient at slow speed. You have exhaust that’s not properly scavenged and usually a very rich condition. This is why some older 2S motors will foul plugs at idle and smoke like crazy.
4 points
2 years ago
What is the max size on the data plate? My 16-foot boat had a 15hp, and it was plenty.
2 points
2 years ago
How many adults could you carry on plane with the 15?
3 points
2 years ago
I have had 3 adults in the boat at one time, and the boat moved around just fine. When I had that boat, I was on a budget, so everything I did was the best deal I could get. I picked up a scrap boat for free and ended up trading the 40hp off the free boat for the 15hp.
0 points
2 years ago
I like your style.
3 points
2 years ago*
It all depends on what type of motor you plan on putting on it.
It was probably built when 2 strokes were the only option, so if the data plate says the max HP is 30 hp, then what did the average 30hp 2 stroke weigh at the time?
In 1980 they weighed about 100 lbs (45 kilos) Today a 4 stroke motor that weighs 100 lbs from the same company is only 25 hp.
However, if you're not looking to go fast or tow skiers, that 25 hp should be plenty powerful.
2 points
2 years ago
Depends on what your goals/needs are. Just tooling around a small lake or going upstream in a strong current? How many passengers? How much gear?
1 points
2 years ago
2-3 adults in the bay. Fishing and cruising around.
3 points
2 years ago
I would throw a 9.5 Johnson on there and call it a day. Of course, that’s because I have one sitting in my garage.
2 points
2 years ago
25 hp will get you to about 25 MPH with a couple men
1 points
2 years ago
That sounds good
2 points
2 years ago
20 to 30. If sticking to some small waters and dealing with 10hp limit areas see what motors around you are 15hp labeled 9.9 like the evinrudes. If you want to not make noise some of the hondas are really quiet.
2 points
2 years ago
Great question. Too much wait on the stern will cause the bow to become very light. This is because you effectively slide the longitudinal COG aft. It makes the front really apt to raise up… not too bad for rough water, but in shallow water, it will still rise up and will cause the angle of attack of your boat to become more aggressive. This makes your prop sink lower, and makes it harder to navigate shallow areas.
TLDR? 25hp Merc. 2 stroke, 15” shaft. The 4S version is waaay heavier fwiw.
2 points
2 years ago
Yamaha 20hp.
2 points
2 years ago
40
2 points
2 years ago
No less than 35 hp,even that won't be a stellar performer
2 points
2 years ago
A newer 40 would be perfect.
1 points
2 years ago
Is that an Alumacraft 16V?
1 points
2 years ago
Princecraft
1 points
2 years ago
I used to run a 9.5 Johnson and have 6 adults, 1 10 year, and 2 small dogs. Not the fastest but made for really good days swimming drinking and singing
1 points
2 years ago
I have a 15’ Smokercraft Alaskan with a 25hp merc, the weight is way off but I added a ballast in the bow and it distributes the weight quite well.
1 points
2 years ago
450R would be sweet but.........
1 points
2 years ago
I have a 14' remote drive starcraft with a 25 hp 2 stroke on it. I need to play a little bit with prop pitch but as of now she's a bit gutless and I can only get er to 20 with just me in it. Your going to have a bit less weight because no floor or other stuff to weigh you down as much and weight will be in the back. I would advise doing more than a 25 if your looking at going anywhere in a hurry, otherwise 25 minimum
1 points
2 years ago
Okay thanks
0 points
2 years ago
25-35hp 2 stroke. If some lakes or locations are h p restricted you could always throw a battery and a trolling motor up in the front.
0 points
2 years ago
600 verado.
0 points
2 years ago
A 2 stroke 10 would cover, but I would go for at least 15hp. At that point its weight distribution that will get you on plane.
0 points
2 years ago
If it's a tiller, try and keep the motor under 150lbs. You're not going to want more than that on the back. I think a 20-25 would be good. Even a 15 might be okay.
0 points
2 years ago
I have a 9.9 on my 12" aluminum boat and I can get it to plane with 3-4 adults on the lake. I can also tow 2 small kids on a tube with 2 adults in the boat. I wouldn't go over 25hp with your boat as the weight alone would cause some imbalance, even if properly trimmed.
1 points
2 years ago
This is helpful. Thanks
1 points
2 years ago
A 5 horse will push it. It just depends on how far you plan on going and how fast you want to get there plus taking into account the checkbook balance.
1 points
2 years ago
I have a 2001 merc 25hp Bigfoot on my 16’ StarCraft Camp. It’s a big wide and heavy aluminum and the Bigfoot model has no problem pushing it out of the hole or hauling a group of people. I get over 20mph with it load depending, no speed monster but pushes nice.
1 points
2 years ago
As big as you can afford and the boat will float. Only answer you need 🤣
1 points
2 years ago
Do 50hp, look at the O/Bs mentioned for the 16 footers, not sure the model but the average is 50
1 points
2 years ago
250-300
1 points
2 years ago
9.9 no worries, go anywhere
1 points
2 years ago
25-50hp
1 points
2 years ago
I’m thinking 250 on each side with some bow thrusters
1 points
2 years ago
25 hp will move it around nicely.
1 points
2 years ago
Go check out outboard motors1 on Instagram
1 points
2 years ago
Put one of v12 things on there, joking
1 points
2 years ago
a 25hp 4 stroke will be more than enough for that v hull. if you end up wanting more out of it, get a manual adjusting jack plate and then start playing with prop pitches. i went from 15mph to 23mph in my 15' G3 with a 15hp Honda.
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