Mud Motor question

chris16371

Petty Officer 2nd Class
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May 19, 2017
Messages
156
Currently my 12' aluminium semi-v has a 15hp Suzuki on it, it doesn't need a lot of water to run in but the prop holds it back from going a lot of places I would like to. Now a jet I'm sure would fix this but do to cost and availability in my area it's not a very good option for me. I've been looking into building a mud motor using a 13hp Honda GX390 or similar but I'm wondering if it will be enough power to push me up stream on the Allegheny River, especially when the water and current is up like now. I live not to far from the Kinzua Dam. Any input would be appreciated!
 

roscoe

Supreme Mariner
Joined
Oct 30, 2002
Messages
21,657
Mud motors work in open water, weeds and muck.
Not good for extreme shallows or rocks.
Also, they hamper maneuverability , as in not good in tight quarters or swift currents in my opinion.

Building one is a lot harder and more expensive than it looks.
Search the forums as there are some detailed threads on home built mud motors.
15 hp or 13 hp, is a lot for a 12'er.

How shallow is the water you are trying to run it?

Probably better with a 1448 jon boat, a it may have a shallower draft, and a motor that is mounted as high as possible.
 

chris16371

Petty Officer 2nd Class
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May 19, 2017
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156
I'm not exactly sure how deep the water is, I'm good in most spots but sometimes it shallows right up and I need to tilt my motor quick, the boat clears no problem but motor does not. To many close calls. Mud motor should clear no problem since there's nothing hanging below prop. I didn't plan on building my own from scratch, if I make one it will be from a twister kit which makes the shaft 50" instead of 100" and from what I've read these kits are pretty simple to install. Just need to make sure it can push me up stream with how fast the current can get. The only thing I don't like is there's no reverse but I could manage without. I do have an ad on some classifieds in my area looking for a 9.9-15 jet motor or a jet foot for my Suzuki, I don't see any resources online that shows that any jet foot is compatible with my DT15.
 

roscoe

Supreme Mariner
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Oct 30, 2002
Messages
21,657
Well, those twister kits, like most mud motors, still need water and they still have (a wimpy) skeg extending below the prop.
Need a foot or more of water to keep the prop in the water.
The props are sold in 3 packs for a reason.

Probably better off with a rock hopper or a river runner prop guard on your current motor.
And raise the motor as far as you can and still keep the water pick up under water..

A jet drive will cost you quite a bit in $, and cut your horsepower by 30%.

There is a jet unit that will fit the dt9.9 and 15. Don't know if they are available here in the US.
 

chris16371

Petty Officer 2nd Class
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May 19, 2017
Messages
156
A jet drive on my 15hp dropping approx. 30% would still give me approx. 10.5 horse which should still be good for a little 12' aluminium. Just don't know where to look for the jet foot.

I did find a jet unit that uses a 8hp Briggs engine and Otterbein unit, the Briggs engine though is about blown up but should be easy enough to replace. Does the same 30% drop apply? If I bought a 15hp vertical shaft engine and mounted it to the Otterbein unit would I get about 10.5hp?

I appreciate the insight on the mud motor, the way people talk is that they can be run in really shallow water and that the prop is about even with the bottom of the boat so I thought it was exactly what I was looking for. Good thing I didn't just buy everything without asking questions first.
 

roscoe

Supreme Mariner
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Oct 30, 2002
Messages
21,657
Yes, any jet drive will reduce the hp by 25-30%
Just the inefficiency of the jet.

For what its worth, those air-cooled Briggs engines are very loud.

good luck.
 

Sea Rider

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Sep 20, 2008
Messages
12,345
Don't think that will find any commercial jet drive for such a small portable outboard, are usually found in the 25 + HP outboard range. If going for a mud motor Briggs type install a prop that makes engine to rev at max wot range to get the max stated horses out of them.

Happy Boating
 
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