speed ideas?

niss_det

Seaman Apprentice
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Feb 12, 2007
Messages
31
Re: speed ideas?

BF said:
maybe this is all troll-bait, but hmmm, 40 hp on a boat rated for a 6.5 hp.... I have a 12' shallow tinny cartopper like that. It usually has a 6 hp on it... I put a 15 hp on it (to test run the new to me motor), and I'm sure it did ~30 mph (felt like 90). It was on calm like glass water, and once I got close to warp 3, I noticed the whole bottom of the boat dishing up.. .only about the last foot was touching. That's when I figured I'd been lucky until that point and idled it back in.

There's a big difference between 12' boats rated for 10 or 15 hp, than those rated for 6.5 hp.... a 40 hp on the more sturdy boats would be madness, a 40 hp on your boat... well that's a whole 'nother level of madness.

If you are serious about running it (which I doubt), make sure you rig a kill swich thingy that attaches to you, so you don't let this thing fly into someone else once it dumps you out. (oh and take video)

i am 100% serious.. the motor is on the boat right now as i type this.. but i will have a friend record me on my little adventure when it warms up enough.. and i do have plans on having a kill switch tied to me if i end up going overboard..
 

Frank Acampora

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Jan 19, 2007
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12,004
Re: speed ideas?

What a bunch of wusses! When I was young I put a rude 20 on a 6 foot jon boat. Gas tank in front and I had to sit between the seats. The boat did a measured mile in about 1 minute. lotsa fun until I flipped it-- and the rude kept running. Didn't get hurt though. Luck is always with the stupid. Now I'm older and more sane and use bigger boats--55 on a ten foot tunnel hull.
 

niss_det

Seaman Apprentice
Joined
Feb 12, 2007
Messages
31
Re: speed ideas?

Frank said:
What a bunch of wusses! When I was young I put a rude 20 on a 6 foot jon boat. Gas tank in front and I had to sit between the seats. The boat did a measured mile in about 1 minute. lotsa fun until I flipped it-- and the rude kept running. Didn't get hurt though. Luck is always with the stupid. Now I'm older and more sane and use bigger boats--55 on a ten foot tunnel hull.

finally a positive comment lol!!! and here is a pic of the motor on the boat so you all know im serious.. this was right after i changed out the old plywood with a new piece of 2x12.. just a few more braces and she will be waiting for warmer weather..
DSC01747.jpg
 

WillyBWright

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Dec 29, 2003
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8,200
Re: speed ideas?

Wear a PFD! That's the size boat I didn't try it on. I don't see a tiller handle. Are you putting steering in? I don't endorse the broomstick idea. :%
 

niss_det

Seaman Apprentice
Joined
Feb 12, 2007
Messages
31
Re: speed ideas?

WillyBWright said:
Wear a PFD! That's the size boat I didn't try it on. I don't see a tiller handle. Are you putting steering in? I don't endorse the broomstick idea. :%

i am def gonna wear a vest.. and i still need to get a tiller handle i wolnt use the broomstick idea.
 

Frank Acampora

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Jan 19, 2007
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Re: speed ideas?

Advice: From my experience with the jon boat. Keep a very firm hand on the engine. Don't try to turn it . that's how I flipped mine. I made a correction from straight and it got wiggly. Then the engine turned and flipped the boat. 360 --it ended upright and full of water with the engine still idling in gear. October--no one on the lake--me fully clothed- no pfd--touch and go to paddle it the 50 yards to shore. Young and dumb and full of---
 

Scaaty

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May 31, 2004
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Re: speed ideas?

Chinewalkers first paragraph says it all. I picked up a shortshaft 20hp (that looks like 20inch your pic..even worse) Johnson, and wanted to try it out. Only thing available was a 12 foot aluminum rowboat. Like a damn light switch, almost tossed me out the back...been on water for 50 years, and I went straight back to the dock. It was uncontrollable.with a tiller. Steering and a foot throttle would be the only way to go, but your project is simply dangerous
 

niss_det

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Feb 12, 2007
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Re: speed ideas?

well i want to say thanks for everyones concern.. you all prob think im just some young punk with very little or no experience on the water..i have been boating ever since i have been a little kid and i have much respect for the water. i am not trying to harm myself or anyone else with this project.. this is the first project i have ever tried with a boat everything in the past has had an i/o and been setup from the factory.. i am constantly looking for outher boats i def want to get something i can ski behind again. i origanally picked up this boat for a local shallow water river to use for fishing and when i was given this 40hp outboard for free its the only boat i have to attach it to..
 

deejaycee_2000

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Mar 28, 2006
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Re: speed ideas?

no one thinks your some young punk ...... there are just some of us here (like me) that have tried the craziest things that seems impossible and luckily lives to tell the tale ...... lol ..... as long as you believe in yourself .... no one thought I would be able to run my 8.5 foot inflatable with my modified 30hp, but I knew I could do it because I redesigned my inflatable to make sure I can run it WOT with that motor ..... currently I run it 46 mph at WOT and very stable, can do 90 degree turns and everything ..... it is alot of fun to outrun a 115hp hahahaha ..... I am still going to add a 70hp to it, one of my engineering buddies are trying to find a way to shorten the shaft for me as I need an extra short shaft for such a little inflatable ..... after a couple of minor mods to my inflatable I would be able to run fine ...... hopefully ...... so good luck ... nothing is impossible ..... up your life insurance (my wife can retire IF i die)
 

Scaaty

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Re: speed ideas?

Trouble here in the boat hull. 12 rowboat style has all the directional stability of basically a soup bowl getting shoved across the water
 

BF

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Re: speed ideas?

anyway, your pict shows me that it's not just troll-bait... :) No I didn't think you were a young punk, but I did think the post sounded like it came from someone without too much boat experience... the rig you've put together is nothing like a stock I/O...

Just curious, do you see this being just a novelty "lets see how fast it will go" thing, or do think you'll actually be using the boat for fishing skiiing or whatever with the 40 on it? If it's just a go fast for fun thing, maybe you should consider building yourself some kind of tunnel hull out of plywood... tons of plans for those around. They'd handle speed better, and don't worry, they'd still feel scary. If you actually want to use it as a boat, you'd be better off looking for a cheap/free 14' fiberglass runabout to put the motor on. They can be had for near nothing and if needed, the transom, floor and stingers can all be replaced to make 'em sturdy again. There's been one (boat only) for sale locally for a long time for $200. When the motor dies on an old rig, the boat and trailer don't fetch much for re-sale. Often they still have the steering and decent seats etc...

I'll admit I've had my own moments of insanity with powered things, but IMHO, your rig just looks like bad news.... it'd be a shame to toast a good motor on an experiment gone bad... but you seem to have made up your mind, so good luck.
 

River - Runner

Petty Officer 1st Class
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Mar 26, 2005
Messages
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Re: speed ideas?

Heed the other members warnings about your setup! Experience is a teacher, for I also have stories to tell. Get a boat rated for your motor, period. There are small light tinny's built for it.

Pic's of mine. A 14' FD Alumacraft, utility. Boat weight 207 lbs. Narrow 4 1/2' beam with round (soft) chine and 15" aqueduct transom. It can easily handle the power. I had this boat 39 years and bought mine because my uncle has one. He has his 51 years now and currently with 35 hp.
FDrearmotorupPB.jpg

FDleftanglePB.jpg


A pictured 14' FD Alumacraft with 2 Mercury Mark 55's on the transom, courtesy of vintagealumacraft.
FDwith2MercuryMark55s.jpg
 

niss_det

Seaman Apprentice
Joined
Feb 12, 2007
Messages
31
Re: speed ideas?

BF said:
anyway, your pict shows me that it's not just troll-bait... :) No I didn't think you were a young punk, but I did think the post sounded like it came from someone without too much boat experience... the rig you've put together is nothing like a stock I/O...

Just curious, do you see this being just a novelty "lets see how fast it will go" thing, or do think you'll actually be using the boat for fishing skiiing or whatever with the 40 on it? If it's just a go fast for fun thing, maybe you should consider building yourself some kind of tunnel hull out of plywood... tons of plans for those around. They'd handle speed better, and don't worry, they'd still feel scary. If you actually want to use it as a boat, you'd be better off looking for a cheap/free 14' fiberglass runabout to put the motor on. They can be had for near nothing and if needed, the transom, floor and stingers can all be replaced to make 'em sturdy again. There's been one (boat only) for sale locally for a long time for $200. When the motor dies on an old rig, the boat and trailer don't fetch much for re-sale. Often they still have the steering and decent seats etc...

I'll admit I've had my own moments of insanity with powered things, but IMHO, your rig just looks like bad news.... it'd be a shame to toast a good motor on an experiment gone bad... but you seem to have made up your mind, so good luck.



this is just something to play around with.. i dont expect this boat to handle well just something i gotta try.. ill prob end up going back to my original plans for this boat and put a jet drive on it i just gotta find a motor to turn it.. like i said earlier i used this boat all last summer mainly for a shallow river to fish but my trolling motor doesnt have the power to move me upstream and im constantly beating it off of rocks.. if the jetdrive will get it on plane i should be able to get just about anywhere with such a shallow draft.. and no i dont plan on trying to ski behind this even tho it would be real funny..
 

Scaaty

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Re: speed ideas?

Now THERES your answer...jet drives have no torque problem..
 

River - Runner

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Messages
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Re: speed ideas?

niss_det said:
yea i knew that the boat was only rated for 6.5hp so i went ahead and made everything stronger.. the transom use to flex alot but not any more.. i just hope the rest of the boat holds up lol.. i might end up just keeping a lifevest on the motor incase something happens i can deal with loosing the boat.. id like to keep the motor

A 6 hp. should be ideal for your boat. I also fish shallow fast river current and will use a 4 hp. motor. They're the best fishing motors for a small boat.

A pic of my same boat with 4 hp. With a light load it will plane it.
Dcp_143940.jpg


Don't do the jet, the motors are too big and heavy for your boat. You also lose 30% of thrust compared to a same propped motor. If you run your 40 hp., you need to get a boat for it. I suppose it's not what you want to hear, but it's my thoughts.
 

niss_det

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Joined
Feb 12, 2007
Messages
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Re: speed ideas?


A 6 hp. should be ideal for your boat. I also fish shallow fast river current and will use a 4 hp. motor. They're the best fishing motors for a small boat.


Don't do the jet, the motors are too big and heavy for your boat. You also lose 30% of thrust compared to a same propped motor. If you run your 40 hp., you need to get a boat for it. I suppose it's not what you want to hear, but it's my thoughts.

[/quote]


i really dont think anything but a trolling motor with a flex shaft would work besides a jet drive in the river i fish.. it gets wide and very shallow in alot of places and its real fast almost rapids prob like 4" deep so a solid propped motor would just get distroyed the scag would be gone in a short time.. if i go with the jet drive im not looking for speed i just want the ability to get around.
 

River - Runner

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Re: speed ideas?

I think the smallest jet is 20 hp., which is a 30 hp. motor. That's why I say, too big and heavy for your boat. A jet pushing needs rpm's on it to work and you can tear up the bottom of your boat without a skid plate. It works best on a boat made for it. I like the tunnel hulls.

I also run through very fast current and skinny water with sharp rocks and sand. If I can float my boat, I can get through. I have 2 trolling motors, front and rear, and use them to pull the boat either forward or backward for control in current. When it's real shallow I'm up front working the front bow motor that the prop just bites the water to pull the boat forward to get through. Sometimes if I can't make forward progress because of strong current the front of the boat might swing around, then a uncontrolled drift happens. So before that happens, wearing waders, I'll get out of the boat and pull it through. With my light boat, I can go some places where jets and air boats won't and I will also use a push pole to get there.

I think your boat would work best with a small outboard with shallow water drive and a front trolling motor setup. Some have a lot of power! Or for the 40 hp. motor get a boat for it and do the same.
 

Mark42

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Re: speed ideas?

That 40 hp weighs closer to 180 lbs than 140 lbs.

you might consider some trim tabs to help keep the bow down.
 

WillyBWright

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Re: speed ideas?

That 40 would be awesome on a 14' Jon. Possibly even faster than on the 12. :)
 
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