my idea for a jet jon build will it work?

amk
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my idea for a jet jon build will it work?

Post by amk »

I have a 1648 alumacraft and a Yamaha 650 cc jet motor the boat is riveted but will be sand blasted and welded a bit to strengthen. My main concern is top speed most people use a 8 or 900 will this be enough? Will I have to remove the pods I'd like to keep them.
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He Reigns
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my idea for a jet jon build will it work?

Post by He Reigns »

How many horse power does it have? My 16/44 has a 750cc with 80 horse and a 148 mm pump and it is plenty from what we have tested so far. It also depends on what you are hauling in the boat and what you want it to do.

montanaman
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my idea for a jet jon build will it work?

Post by montanaman »

done right it will work very well
done a few of them with this engine and they would push along at 31-32 mph wot with the guys in the boat

amk
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my idea for a jet jon build will it work?

Post by amk »

Not sure on the hp but I will mostly be running a shallow sandy rocky river most places are 1-2 ft there are holes that are 15ft deep and occasional shallow spots that are 2-4" deep. If it goes in the thirties with me two guys and a cooler I will be all :mrgreen:

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He Reigns
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my idea for a jet jon build will it work?

Post by He Reigns »

I did a quick google search, looks like most of the Yamaha 650's are 50 horse with a couple models at 42 horse.

amk
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my idea for a jet jon build will it work?

Post by amk »

how fast does yours run and how does a 100cc difference almost double the hp kinda weird.

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JL8Jeff
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my idea for a jet jon build will it work?

Post by JL8Jeff »

I had one of those Boston Whaler Rage jet boats (1992-93 I think) with the Yamaha 650 and I installed a "wake up" kit from Pro-Tec which included an exhaust pipe, higher compression head, carb modifications and air filter. I added an MSD igntion and that boat moved along nicely! It was a little loud after the mods so I added a water silencer to quiet it down a bit. I was going to do an impeller but never got around to it.

Found a couple old pictures of the modified motor.

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2001 Lowe Roughneck 1652 VT with Merc 60/45 jet 2 stroke

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He Reigns
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my idea for a jet jon build will it work?

Post by He Reigns »

I don't know about the hp ratings, I have seen some around 700cc rated at 100 hp. All I know is what I read. Mine run at about 35 fully loaded on the first test run with fuel issues, second test run is tonight and speed will be checked with GPS. Check out my build thread in jetboats. Links to build videos on YouTube in the thread as well.

amk
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my idea for a jet jon build will it work?

Post by amk »

ok thanks I look forward to your speeds. Im purchasing the motor with all the wiring and pump for 600 which I think is a good deal so I'ma run it till it blows up then buy a bigger engine they are cheap enough.

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PSG-1
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my idea for a jet jon build will it work?

Post by PSG-1 »

I'm thinking those Whaler Jets used a 700cc engine.

As long as you keep the weight to a minimal amount, the 650 should push you long at a good clip. Using an engine that small, I would recommend staying with a smaller diameter pump (if you use another type of pump besides what's in the jet ski) The smaller engine can wind out the smaller pump to max RPM without putting as much load on the engine. You can also experiment with impeller pitch and that will give you some more top end, as well.
ALUMA-JET project:
https://www.tinboats.net/forum/viewtopi ... 21&t=22023


Fishing, jet skiing, target shooting, jet-boating, and even a little oyster harvesting with Larry The Cable Guy.
Watch it all right here:

https://www.youtube.com/user/HKPSG1Shooter?feature=mhee

amk
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my idea for a jet jon build will it work?

Post by amk »

The pump in the picture I have no idea what it is can anyone recommend an ideal size pump and impeller with pitch?

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PSG-1
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my idea for a jet jon build will it work?

Post by PSG-1 »

The engine in the pic is an engine in a Boston Whaler Jetboat, the 14 foot "Rage" Again, if memory serves me correctly, they use a 701 cc yamaha engine (same as what's in my super jet)

Pump size.....go with smaller diameter, such as Yamaha 144mm. Don't use a 155mm, that's too large for the size engine you are using to turn it. I would go even smaller than a 144mm, but I don't think you can find any bolt-in pumps/ducts that are smaller than 144mm. Using a small engine, you don't want to over-lug it with too large of a pump,or you'll be replacing engines. Think of it like putting a 7" grinding wheel on a 4" grinder. Yeah, it will turn it, but that grinder doesn't really have the mass, or motor, required to be able to turn it for sustained periods, and it will eventually burn out the motor. Same with putting too large of a prop on an outboard, or too large of a pump on a PWC or jet boat.

As for impeller pitch, hard to make a recommendation on the exact pitch you need. However, I would advise using a swirl-type impeller, as they are less prone to cavitation, and they also have a lower tendency to foul in light grass, versus a conventional impeller with its straight leading edges.

Talk with the folks at Impros, this is what they do for a living, they can likely recommend the correct pitch, or even re-pitch your existing impeller.
ALUMA-JET project:
https://www.tinboats.net/forum/viewtopi ... 21&t=22023


Fishing, jet skiing, target shooting, jet-boating, and even a little oyster harvesting with Larry The Cable Guy.
Watch it all right here:

https://www.youtube.com/user/HKPSG1Shooter?feature=mhee

amk
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my idea for a jet jon build will it work?

Post by amk »

Thanks I will check into what size that pump actually is. Does that wake up kit hurt the reliability of the engine by adding to much stress or is it a good idea to add.

amk
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my idea for a jet jon build will it work?

Post by amk »

Whats the best place to order the pump and impeller I need?

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PSG-1
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my idea for a jet jon build will it work?

Post by PSG-1 »

Try to find a PWC warehouse/junkyard where they part out old PWC's. This is your best bet, and will save you a substantial amount of money.

I have a friend who operates a PWC warehouse just a few miles up the road from where I live. He would be able to tell you the best setup to run with that particular engine, as well as the info about wake-up kits, and other performance mods, since that's his other specialty.

Here's his number:

(843) 651-7977

Best to try him in the late afternoon/evenings.
ALUMA-JET project:
https://www.tinboats.net/forum/viewtopi ... 21&t=22023


Fishing, jet skiing, target shooting, jet-boating, and even a little oyster harvesting with Larry The Cable Guy.
Watch it all right here:

https://www.youtube.com/user/HKPSG1Shooter?feature=mhee