new to iboats

cleve

Petty Officer 2nd Class
Joined
Sep 18, 2008
Messages
156
hello everyone, i am new to the site,but i've been reading the forums for a while and have found there to be many knowledgable people on this site. i have a lengthy question about my situation and i hope i'm posting in the correct forum, so here goes. i have a grumman 1648 with stick steering and a 40 2 stroke johnson(1998).i've been looking to upgrade to a 50 or 60 for more power,mainly top end(getting 30 to 33 mph with johnson) and can't decide what to do. my friend has a 50 mercury 2 stroke on a 17' fisher crappie boat and it really moves, probably 35-37 mph, and i like a mercury. now, another friend of mine wants to sell his 2004 yamaha 60 with all the controls and the heavy duty stick for $3000 which i think is a deal. went and drove his boat(1655dlx c. skiff) the other day and was not real impressed with the speed. it has plenty of pop to get on plane and runs and idles great but top end speed was lackluster.he has a 17 pitch prop and said the best mph he got on the gps was 37. can anyone take a stab at how fast it would push my boat and maybe go with a 19 pitch? i know the carolina skiffs are big heavy boats and maybe that's why his is slower. another option i thought of was to convert my 40 to a 50 if you can do it.i think that model year(1998)the johnson 40 and 50 were the same engine. should i go with a new merc. or e-tec,buy the yammy,try to upgrade my 40,or just shut up and be happy with what i've got.i'm not looking to drag race or anything, but i am wanting to get faster on the water, at least 40 mph with two people because i fish a lot and we run all over the lake sometimes. any input would be appreciated. thanks in advance.
 

tashasdaddy

Honorary Moderator Emeritus
Joined
Nov 11, 2005
Messages
51,019
Re: new to iboats

1st what is the max hp rating for your boat? you do not want to exceed that. many complications. this is why.

The United States Coast Guard has an opinion on this frequently asked question, and their answer from their website is reproduced below:
Can I use a bigger motor on my boat than what it's rated for?
It is not a violation of Coast Guard regulations to install or use an engine larger than specified on the capacity label, but there may be state regulations prohibiting it, and restrictions from your own insurance company regarding this.
There are no Coast Guard regulations against exceeding the safe loading capacity, however, there may be State regulations or restrictions from your insurance company which prohibit this. There is a Coast Guard regulation that gives Coast Guard Boarding Officers the power to terminate the use of a boat (send it back to shore) if, in the judgment of the Boarding Officer, the boat is overloaded. There is no fine for this, unless the operator refuses the Boarding Officer's order. We certainly hope that you will abide by the rating, as overloading may lead to capsizing or swamping of the boat.
NOTE: The Coast Guard Capacity Information label is required only on monohull boats less than 20' in length. The label is not required on multi-hull boats, pontoon boats (catamarans), or on any sailboats, canoes, kayaks, or inflatable boats, regardless of length.
As the Coast Guard mentions, local regulations may apply. For example, in the state of Ohio one should be guided by this regulation:
Capacity Plates
(ORC 1547.39 & ORC 1547-40)
No person shall operate or permit operation of a watercraft in excess of any of the stated limits on the capacity plate. When no capacity plate exists, no person shall operate or permit operation of a watercraft if a reasonably prudent person would believe the total load aboard or the total horsepower of any motor or engine presents a risk of physical harm to persons or property.
 

haskindm

Petty Officer 1st Class
Joined
Jun 12, 2008
Messages
255
Re: new to iboats

To me, 40 mph in a light aluminum boat would be downright scary, but to each his own. You cannot change a 40 HP to a 50 HP without spending a ton of money. It would be cheaper just to buy the engine that you want. The difference in time between 35 mph and 40 mph is negligible, so only you can decide it it is "worth it". Whatever you do, you will need to spend some time experimenting to get the right prop and you must use a tachometer. I don't know of any shortcut to the right prop and the prop can make a HUGE difference. You may want to start by making sure you have the right prop on your rig now.
 

cleve

Petty Officer 2nd Class
Joined
Sep 18, 2008
Messages
156
Re: new to iboats

my boat is rated for a 40 but only because in 1998 there was no stick steering rated above 40 h.p. With the advent of the 70 hp stick earlier this decade h.p. ratings for boats like mine have risen. my boat is a factory rigged fishing boat with carpeted floor and sides, not just a jon boat. 40 mph is not that fast on a boat like mine, but there are plenty of people around here that are running 50 h.p. or more on 14' jon boats and some are going 50mph +. insurance is not an issue for me.
 

jbjennings

Captain
Joined
Jul 18, 2007
Messages
3,903
Re: new to iboats

I can't visualize your rig....I crave pictures.
Here's a pic of my 15ft aluminum boat with a "new" 25hp on it. That's all the motor that boat needs. Surely folks aren't going 50mph in a boat smaller than this. I don't know how you could get this boat over 35 or 40 without the front coming back over on top of you when the wind picked it up!:)
If you want a speedy boat, why beat around the bush? Go buy you a different rig with a 115 or a 150 on it. A 50, 60, or 70 isn't really made for speed, just pushing more weight.
Just my opinion,
JBJ
 

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cleve

Petty Officer 2nd Class
Joined
Sep 18, 2008
Messages
156
Re: new to iboats

i know a man that has a 14' jon boat with a hopped up 40 tohatsu and he's had it at 54 mph. he took out the bench seats and mounted a seat in the floor at the rear of the hull. i personally would not have such a death trap, but 40-45 mph in a 16' hull 48" bottom,full flotation, and 20" transom is easily acheived with the right motor and prop. like i said, i'm not wanting a boat to run with the rangers and nitros, just more power, mainly with 2 people and fishing gear because my johnson(2 cylinder) struggles with added weight. i did not want to buy the yamaha if i was only going to go 4 or 5 more mph. with the yamaha on my lighter,semi-v, aluminum hull will it push it in the 40's versus 35-37 mph on the heavier,wider,flat-bottom carolina skiff?
 

haskindm

Petty Officer 1st Class
Joined
Jun 12, 2008
Messages
255
Re: new to iboats

You asked for advice, you got it, and didn't like it. You've made up your mind so put any engine on it that you want. The manufacturer put a rating on it, if you exceed it you do so soley at your own risk. As others have said, it sounds like you have the wrong boat.
 

Benny1963

Lieutenant
Joined
Sep 17, 2006
Messages
1,476
Re: new to iboats

its not worth the effort i have tried several setups
14 alumacraft with 1973 50 15 inch mid and small alum jackplate
it had the 42 inch bottom ran 46 mph gps was dangerous as hell
also ran a 16 with 52 inch bottom with 85 and 115 crossflows
boat ran 42 with a little left but due to weight and design it handled pretty good ,but extra weight on the transom is not to good
i would set the boat up to run max horsepower on tag
then fine tune your setup good prop smart tabs small manual jackplate
and water pressure gauge pick your motor up till ya get it right or until waterpressure drops then back down prop selection
is a must , but then again i have a 17ft mckee classic with 175 crossflow
unfortunaly its the only motor i have i am looking for smaller motor
and good bass hull for my 175 so good luck and be carefull
 

d.boat

Chief Petty Officer
Joined
Sep 19, 2008
Messages
520
Re: new to iboats

my boat is rated for a 40 but only because in 1998 there was no stick steering rated above 40 h.p. With the advent of the 70 hp stick earlier this decade h.p. ratings for boats like mine have risen. my boat is a factory rigged fishing boat with carpeted floor and sides, not just a jon boat. 40 mph is not that fast on a boat like mine, but there are plenty of people around here that are running 50 h.p. or more on 14' jon boats and some are going 50mph +. insurance is not an issue for me.

This is an honest question: Do you currently carry any liability insurance? (homeowner's and/or umbrella liability, for example). If so, what would happen if you had an engine on there that exceeded the capacity, you were boating with a friend and crashed or flipped? Your friend, or his estate could sue you and your insurance company might not cover you for liability because you exceeded the capacity of your boat. Do you have any assets to lose? How would you feel if your friend were injured and you didn't have any insurance that not only protected you, but also could reimburse him or his family for injury or other loss?

This may seem like a silly question, but it is a real life scenario. That's what people mean when they talk about insurance. They aren't talking about insurance that protects the loss of your boat or motor, they're talking about your liability insurance covering you if you exceed the load or HP capacity.

If you have ANY assets at all, you owe it to yourself and your family to at least ask your insurance company about this.

I'm not trying to say you shouldn't go as fast as you want on any boat you have. Have fun, it's really your own business. But liability is an honest question.

One thing you might do to test your theory that the 40 HP capacity rating is an arbitrary one based on teh largest tiller steer motor available then - plug your boat's dimensions into the USCG formula and see what it comes up with.
 
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