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Discussion Starter · #1 ·
I've seen pictures of the small 6J jets. Anyone know how much HP they are rated for? How little HP could spin them? I'm thinking about a project that would need a little jet. I'm wondering if the pump out of a junk older jet ski would work, but I think they need so many rpm to build thrust that it might not be practical. Anyway, any info would be appreciated.
 

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JRPM/e-PerformanceMarine
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I've seen pictures of the small 6J jets. Anyone know how much HP they are rated for? How little HP could spin them? I'm thinking about a project that would need a little jet. I'm wondering if the pump out of a junk older jet ski would work, but I think they need so many rpm to build thrust that it might not be practical. Anyway, any info would be appreciated.
If I remember right some of the new skis are making are around 200+hp. I bet you could do some trick stuff with one of those newer pumps to work well.
 

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Discussion Starter · #4 ·
I'm actually looking on the lower end of power, a couple of projects that are so far only in mind, not in action! Could 5 HP spin a jet enough to produce usable thrust? 20 HP? I'm just trying to get an idea of what is possible.

Doc, no idea of diameter.
 

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Dave Jones @ Aggressor and I have talked about these pump quite abit over the year. I would not be surprised if he has a few layin in a corner of his shop somewhere. But then again Jim Brock of Cyclone Marine may have one too.
 

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I'm actually looking on the lower end of power, a couple of projects that are so far only in mind, not in action! Could 5 HP spin a jet enough to produce usable thrust? 20 HP? I'm just trying to get an idea of what is possible.

Doc, no idea of diameter.
Just for referance some of the early jetskis only made about 30hp or less.
 

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I had one of these I took from a SKEE WEE (a self propelled Riderless device) that look kind of like a 6' boat:D it was powered by a 2 cylinder Kohler snow mobile motor and had 50 feet of control cables Need less to say it was designed to pull a single skier (they apparently were banned in the 60's)

Anyhow I sold it (the little jet) to a guy in the mid west who coupled it to a Honda air cooled V4 In a Canoe so'as he could run up a river to some otherwize inacessable hunting or fishing spot Some where I have pictures he had to put a "device" (flap) behind the jet to try to control this thing (somewhere I have photos) Tom
 

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I've got three of them right now, two with aluminum impellers and one with a bronze impeller. I started a post on these about a year ago putting as much info on the forums as i could find.

http://performanceboats.com//showthread.php?t=25118&highlight=berkley

My plan is still to put one of these into this 10' little boat i have.

If i remember correctly the skat-trak impeller was rated for around 80-100 HP. I've been told i'm going to overpower the pump with my mill (est 130 HP when done)
 

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Discussion Starter · #13 ·
Steve, thanks for posting the info sheets, very helpful!

Tom, if you have those pics I'd be interested. One of my ideas is to put one in a jon boat type hull. The small transom would make it easier to mount than on a canoe, still a very light boat. Power is the question, figuring out what kind of engine is best suited to spin the jet. I'm even thinking of a little diesel as a possibility.
 

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Discussion Starter · #14 ·
Shaun, I read through your thread, you really took some time to look closely at the pumps. Sounds like you already have the small boat install in mind.

What would be the pros and cons of using a jet ski pump instead of a 6J? Not an early jet ski, maybe from a late '80's model. I've never looked closely at one.
 

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Shaun, I read through your thread, you really took some time to look closely at the pumps. Sounds like you already have the small boat install in mind.

What would be the pros and cons of using a jet ski pump instead of a 6J? Not an early jet ski, maybe from a late '80's model. I've never looked closely at one.
Click project mini in my sig and you'll see what i have so far. Right now a 10' boat, a couple of those pumps and a ford v4 motor. Plan is to make a mini hotboat!

I originally was going to use a jetski pump, infact i still have the ass end of one that i cut up in my backyard. The problem with the jetski pumps is that there is no intake/suction on them. The hull is basically the intake/suction and then the bowl bolts to the hull. I've been told that one jetski manufacture has a hull that it's seperate but i havnt seen one yet.

This is what i'm going to put one of those pumps in.



and here's the v4 i found (18" long total)


all stripped down
 

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Too much work for the poor performance....

I used those "6J" pumps back in the 80's on some little boats we built. I had to install Scat stainless impellers and do about 1 1/2 hours of 'cleaning and blending' to get a 2 cyl 85 HP two stroke motor to run these boats 35-38 MPH. The stock impellers look like a fence post hole auger and work exactly as well. If your project is going to be "just a small kid's toy", then that jet is OK. BUT if you really want the boat to run with any kind of real power, that jet (IMHO) is an expensive waste of time and money. The blue openbow is a jet, (35/38) (so is the black and white) the black and yellow is a Tohatsu 40, (43) and the red is a surface drive that we designed. (58)
 

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