Have speed, water pressure and a new engine

[ncclaymaker]

About four years ago, September 2011, I bundled together an old Sears & Roebuck Jon boat, a somewhat damaged Mastercraft WetJet jet ski to create a Swiss Army knife made for the lakes, rivers and deep creeks of North Carolina. Well, the engine pretty much died from lots of use, not lack of maintenance. This rig got me into places that most people can only dream about... 12" to 16" water. This past month, I bought a "new to me" jetski that was old, but hardly used. for $150. Thank you Craigslist.

This is the rig with the Brut power plant. The nozzle at the stern/rear of the boat I use to get me to where I think I might want to be, and powers the suction log for the sluice when I get there. The output was great and effortless, considering that the pump was harnessed to 50hp.



I figured that maybe a few, if any might be interested in how I assembled the next gen beast. Below is the old jet nozzle and the newer Bombardier-Rotax engine. Logic has it... why carry or lug a separate pump and junk, when you can use the one that gets you to where ever you need to be. This newer engine is 55hp, twin carbs instead of one and more midrange torque. When the drive shaft gets back from the machine shop... this rig will move the boat, sand and gravel like it's on steroids.





I'm still looking for a safe and durable means of transporting the sluice w/classifier. But, thanks to a totally different thread, "Va river prospecting" by mgumby16, he seems to have had a towing issue, that drew my attention to a four year old problem that I've had. Bringing the equipment with me in a reasonable manner. But not on the boat.

while I was removing the "new" 55 hp engine from the jet ski hull, I noticed how light the fiberglass hull assembly was without the engine. So, I plan to cut the hull at the deck line, and then replace the top/superstructure with a piece of marine plywood. I would then mount the sluice w/classifier onto the deck of the hull. In an effort to keep the center of gravity low, I'll create a well in the deck to store 5-10 gallons of fuel. This should help with preventing those nasty tip-overs and submarine mounted sluices. Would love some feedback on the idea with pros and cons alike.


Seadoo XP without almost everything.

Chances are, without having seen this thread, "Va river prospecting", I would have already have cut the hull up for easy handling at the landfill.

 

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[Bonaro]

Hmmm...I have seadoo XP in the back yard with a sick engine and I have been ciphering this very project in my head for a good long time now. Only I wanted to find another XP and install twin engines into a larger sled boat. If you go on ebay you can buy a 95 and newer nozzle with a reverse bucket to give that old XP ability to back up

 

[russau]

HMMMM?? Ive been eyeing a old pontoon boat for a coupe of years around where I live. I keep thinking of a 5 inch dredge underneath and between the pontoons for a trip up the Misery River in the fall when the water levels go back down, BUT then I wake up and look at my 4 inch dredge that hasn't gotten wet in several years now because im a F.O.G. kinda guy!

 

[ncclaymaker]

The biggest issue that I have with the Seadoo XP, was that the intake was designed and built as part of the hull. Notice that I kept the Mastercraft pump unit. I'm not a big fan of cheap, ineffective designs that Seadoo did on this model. Easier to have the drive shaft modified and install a coupler, than use their sad, hazardous design.

 

[Hoser John]

Because boys just gotta have fun. A fella here in Redding used a similar setup to dredge below the Keswick Dam but got caught and lost it all BUT many pounds for 3 years prior to that though. Lotza luck-John

 

[fowledup]

Nice build! I like that yours is missing the case of silicon I see in the ones that guys try to use the JetSki hull/intake in. We have quite a few of those conversions running the Sacramento and other rivers around here, your not giving your engineering enough credit, they run those suckers in 4" of water like it's nothing, amazing boats.

I was looking at the pictures wondering if you couldn't attach a mount with the sluice to the transom that would fold up and over the top of the motor while running then flip down into the water for dredging. Maybe even go with a folding sluice arrangement. Think of a knife blade on a pocket knife. Being attached to the transom you would only need slight flotation at the discharge end mostly for adjustment purposes. My motto has always been - "Man made it, Man can modify it!"

 

[ncclaymaker]

I much prefer to transit the sluice, set it up on the shoreline or creek side. Remember, the pump got me here in the first place, I don't have to lug it or fuel around. But, the major problem of using a jet ski propulsion pump is the sheer volume of water and sand. To fill a 12 foot Jon boat wouldn't take 45 seconds or so. Risk vs. Benefits. After the season is over, I'll be testing a prototype device that I've been developing to replace my sluice box and classifier. It's a variant on an old (very old) device that needs several issues/kinks worked out to make it behave in a manner useful to us, not the laws of physics like it's presently doing. I am not going to create a wheel... just reshape it significantly.

I was thinking of using the ski jet hull to mount the sluice and classifier on... but the hull of the ski jet is way to heavy to be practical as a conveyance. So instead of displacing water on a lake or stream, it'll be headed to the landfill in pieces to displace a little dirt. In a few days, I'll upload the pics with the finished product and the remains of the "organ donor".

 

[Mgumby16]

Glad my "Va river prospecting" helped you!

I love the jet ski jon boat concept and will hopefully one day build one. But I don't know if my 10ft jon boat is the right candidate.

What size and make is your jon boat? Have you run it I anything shallower then 1 ft of water, and have you had any issues with the intake sucking up rocks gravel and sand? Also did you reinforce the jon boats haul to be able to take greater impacts from unseen rocks ?

 

[ncclaymaker]

The draft of my 12 foot Jon boat at idle is about 10 inches at the stern and less than 6 inches at full throttle up. When I go over shallow areas, I back off of the throttle so as not to suck up debris or gravel. The stone guard performs great, but I do carry a spare impeller and a fishing rod just in case. The boat is NOT well suited for creeks and streams due to rocks, logs, etc., but high banking on lakes and rivers or any place that the classifier/sluice can be set up.

With regards to reinforcing the hull. There are only three places that the boat is reinforced - the engine mounts, pump mount/intake port, and the transom. I do carry a caulking gun with a tube of asphalt roofing tar in the event I accidentally slice open a small gash in the hull. I'll upload pics later on showing some details of the rig and how she works.

50hp Brut engine headed to craigslist to be parted out. It'll be new to someone else.

View attachment 1192405

Sawed this one open just like the Veterans Administration did to me(open heart surgery). Difference is that the SeaDoo XP wasn't exposed to agent orange in RVN. Took only several days to transfer the Seadoo plumbing and wiring.

View attachment 1192406

Keeping the old pump because it functions great, and is cast aluminium. Waste not.



New Rotax-Bombardier 55hp engine connected to the pump. This joint utilizes standard PTO connector from AgriSupply. Some machining was required to make a good fit between the pump and engine.




Propulsion controls - Fuel and oil gauge with a separate tachometer, choke and throttle, misc.




Engine, pump assembly secured to the boat.




Sucked clean and is now awaiting its' final ride to the landfill. Waste not. The only part that is not landfill bound is the steering assembly. Will use for the Jon boat.



The second most important part of the boat...a two inch water output to the four inch power suction log. This doesn't require the engine to do much above 25% throttle up to move a lot of sand and gravel. Takes only a minute or two to attach and secure. Beached and well secured with a stout rope and a shut-off tether to kill the engine.

View attachment 1192413

Last, but not least, the highly skilled technical assistant... Ruby the rescue dog. She now has a dogs' life on 5 acres of forest.

View attachment 1192414

Enjoyed creating the beast, now I have to give it the garden hose test... fill her up with about 5-6 inches of water to test for leaks. If all goes well, off to Jordan Lake for trials and a few good bass.