6hp johnson won't plane out my 10' jon boat

[ncfish]

does anyone have any ideas to why my homemade 10'x4'4''x18'' deep, welded aluminum boat won't plane out, it has a livewell in the middle, im running a 6hp johnson, im 225lbs, 3gallon gas tank, deep cycle battery, thats all i had on board. i messed around with the tilt but it diden't help, it felt like a was doing 5mph

 

[Huron Angler]

Re: 6hp johnson won't plane out my 10' jon boat

Got any pics?

My 5.5hp '55 Johnson doesn't plane out my 12' semi-V hull either. I gps'd it at 6.5mph with 2 gallons, two guys and a cooler last weekend.

To plane you could move gear forward possibly, maybe just not enough hp. A 7.5 might do it.

 

[jay_merrill]

Re: 6hp johnson won't plane out my 10' jon boat

Assuming that your boat is flat bottomed, like most jon boats, your J6 should plane it. The first thing that I would do, is to make sure that both of your cylinders are firing. Another possibility is that you carb has problems. You might have some junk in the high speed orifice, or the carb may need to be rebuilt. Checking the fuel pump for proper function is another item worth thinking about, as is making sure that the vent on your fuel tank is fully open.

In the mean time, try to post a pic of the boat and provide us with the model year of your motor.



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[DJ]

Re: 6hp johnson won't plane out my 10' jon boat

Not many 6's will plane anything. Very few 8's will either. 9.9's will plane a lot of boats.

I have a '57' 7.5 that will plane most small tinnies. But, I suspect, OMC was playing the HP game with Mercury, in those days. I think that 7.5 is a "bit" more than 7.5.

 

[torbjorn]

Re: 6hp johnson won't plane out my 10' jon boat

does anyone have any ideas to why my homemade 10'x4'4''x18'' deep, welded aluminum boat won't plane out, it has a livewell in the middle, im running a 6hp johnson, im 225lbs, 3gallon gas tank, deep cycle battery, thats all i had on board. i messed around with the tilt but it diden't help, it felt like a was doing 5mph

We have a 1981 Belgian 6, same as US 7.5 but with restriction from carb to intake. Wouldn't plane our 330 lb glass boat. I opened the intake hole to match the carb outlet, got 7.5 hp. That's a 25% increase, same a going from 60 to 75 hp. It not only planes the boat with 3 people, it runs 16 mph.
The problem is taking off and replacing the starter-that really requires care, is a p-i-t-a. Of course, you have to remove the intake manifold to file out the hole.

 

[DJ]

Re: 6hp johnson won't plane out my 10' jon boat

We have a 1981 Belgian 6, same as US 7.5 but with restriction from carb to intake. Wouldn't plane our 330 lb glass boat. I opened the intake hole to match the carb outlet, got 7.5 hp. That's a 25% increase, same a going from 60 to 75 hp. It not only planes the boat with 3 people, it runs 16 mph.
The problem is taking off and replacing the starter-that really requires care, is a p-i-t-a. Of course, you have to remove the intake manifold to file out the hole.

You are ON YOUR OWN with that advice.

 

[ncfish]

Re: 6hp johnson won't plane out my 10' jon boat

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[F_R]

Re: 6hp johnson won't plane out my 10' jon boat

ncfish, has the motor ever planed the boat? Has any other 6hp ever planed the boat? Sounds like you just don't have enough horsepower. Does it plane any other boat?

 

[ncfish]

Re: 6hp johnson won't plane out my 10' jon boat

[/IMG]i bought the engine from brother (he never used it) i rebuilt the carb, ne impeller, new t-stat, it runs very well. usually starts first pull. and trolls at idle very well.

[/IMG]

 

[ncfish]

Re: 6hp johnson won't plane out my 10' jon boat

what would be to much hp for this boat? i seen a 9.9 on craigslist for 200 but went quick. i know where a 18hp i can get will that be to much?

 

[tx1961whaler]

Re: 6hp johnson won't plane out my 10' jon boat

How far below the bottom of the boat is the anti-ventilation plate on the motor? That is the plate just above the prop....stick a ruler flat under the boat and see here it hits on the motor.

 

[F_R]

Re: 6hp johnson won't plane out my 10' jon boat

Nice job on the boat, it looks great. I am not going to sit here and tell you how much power to put on it though. My main fear is that planing speeds may be too much and dangerous on such a short, hard chined boat. Where did you come up with the plans? What did the designer suggest for power?

 

[rjezuit]

Re: 6hp johnson won't plane out my 10' jon boat

Any idea how much the boat itself weighs? Seems a lot to push with a 6 HP. Rick

 

[ezeke]

Re: 6hp johnson won't plane out my 10' jon boat

I'd be interested to know what propeller pitch you have.

Propellers with pitch as low as 5 have been made that will fit your motor; I think that you can get on plane with one of them.

 

[ncfish]

Re: 6hp johnson won't plane out my 10' jon boat

How far below the bottom of the boat is the anti-ventilation plate on the motor? That is the plate just above the prop....stick a ruler flat under the boat and see here it hits on the motor.

tx, it's level with the bottom of the boat.

 

[ncfish]

Re: 6hp johnson won't plane out my 10' jon boat

Nice job on the boat, it looks great. I am not going to sit here and tell you how much power to put on it though. My main fear is that planing speeds may be too much and dangerous on such a short, hard chined boat. Where did you come up with the plans? What did the designer suggest for power?

fr sorry if i mislead i didn't make it, but a local guy here made it in 96 he now lives in arizona, i just added the lights and upgraded the pumps, carpet and engine, it has trolling motor outlets front and back, i dont know if he ever had a gas engine on it.

 

[F_R]

Re: 6hp johnson won't plane out my 10' jon boat

My guess is that a 9.9 would probably plane it. But I'll also guess that you will be going like the proverbial striped ape once it breaks over onto plane. Getting it out of the "hole" is what is going to take the power.

 

[ncfish]

Re: 6hp johnson won't plane out my 10' jon boat

I'd be interested to know what propeller pitch you have.

Propellers with pitch as low as 5 have been made that will fit your motor; I think that you can get on plane with one of them.

ezek the prop is 8x7.25

 

[McBoatin]

Re: 6hp johnson won't plane out my 10' jon boat

I had a 14ft alumn v-mod that I used on the Iowa river. i miss that boat! i had a 15hp on it and it would plane the boat in seconds with 2 guys but put that 3rd guy on and it would take a good 30sec, going up river was not going to happen.

I need a new lower unit after hitting a stump and so bought a 9.9 at a local market for $200 (what a deal!!)

to the point. I knew the motor would be under powered for my boat so i did some research (thanks iboats) and bought a prop with a lower pitch. provided more power out of the hole and the 9.9 did mutch better than i thought. planed the boat with 2 guys 200-250lbs each going up river.

If you think you are just about to plane, You might just need to try a new prop. see if you can borrow one from the local marina or put out a craigslist add (give a guy $20 to try his prop)

good luck

 

[jay_merrill]

Re: 6hp johnson won't plane out my 10' jon boat

I have a '56 Johnson 5.5 hp motor that once did double duty an an auxilliary motor in a 26 foot sailboat and as the motor that I used on a 9 foot, homemade dingy. The dingy had a flat bottom and was made of plywood and fiberglass. The 5.5hp Johnny planed it easily. The motor was also a long shaft at the time, so there was a lot of drag from the midsection and gearbox sticking down, way below the bottom.

Unless you boat is particularly heavy, I don't see any reason why a 6hp outboard wouldn't plane it. In fact, it should plane at a pretty low speed.

So, my next question is - what does the boat weigh?


BTW, please resize your photos to no more than 640 pixels on the longest dimension. As they are now, most readers will have to scroll right/left, in order to reas the text in posts.



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