Mini OB Boat conversion to Mini Jet Boat

npsteeb, I did not know this. Why do you suggest the 650 XP impeller?

 

You'll be over propped with with the stock XP 787 impeller. That boat weighs double what an x4 does. You won't be able to get the engine at its peak power. If your goal is 50 I think an impeller from 650 would probably work. Plus you'll have a better holeshot

 

I really appreciate the info and heads up. I am going to talk with the shop who built my motor and pump for this build, and see if he has a spare we could swap.

 

More for you all!

Purchased some TAP Plastics products to create a waterproof, durable, buildable product to fill gaps and spaces that fiberglass would simply run out of, or areas that chopped mat and resin could not be laid into properly. I purchased their Microspheres, and Chopped Fiberglass.


They are both filler products that you mix with Polyester Resin to develop different consistencies/mixtures. You could buy similar pre-made products like Duraglass (but its not waterproof) or 3M Marine High Strength Repair Filler, but you can't mix it to your liking. This Microspheres allow you to make whatever consistency you are looking for, and the Chopped strands you can add to reinforce the resin as much as you would like.

This is what I made. A strongly reinforced, peanut butter like mixture.


Filled these areas, that would have otherwise been very hard to fiberglass.




With the light shining through you can see the areas that we packed it into.




Then we added heat with the heat gun to cure it from the reverse side faster. It was laid pretty thick, we didn't want any uncured materials trapped within.




Then we laid a woven fiberglass cloth (tape) over the motor mounts and saturated them with the resin to form ourselves a nice layer that we could build upon to reinforce the motor mounts. You can see the one in the background to see how it looks before being wetted out. This product is very thin, easy to wet and very easy to form without losing its shape.












We let the formula we created cure for just enough to allow us to lay a couple layers of chop mat on. You can see how easy (OK, it wasn't THAT easy...but) the mat lays now with the crevice being filled.




We also reinforced the mounts with a few layers of chop mat.




...and this is how good it looks


but then we did this...and it looked even better.


We had traced the mounts so we knew where not to lay resin. That way we could trim back the cloth and expose the nice flat, original mounting surface.

 

Hi , real nice build
i have a similar project ,10 ft jet.. been stalled a few years but i hope to kickstart it soon.
i look forward to your progress

 

When does your 10 footer date from wreckmaster? I see 06 on the windscreen, is that right?

 

there is no date on the hull, i am not sure of the manufacturer , gotta be 20 years old at least
when i found it there was no motor
..and not much room for one

 

My first guess would be that ur boat was powered by a mercury sport jet. Came in a 65, 75, & 90. 90 would probably be too large for that lil boat. The reason i think it may have been a mercury sport jet is because they were more of a stacked setup where the engine sat on top of the pump. It was more compact that way and may fit in a smaller compartment like urs. Seeing the graphics on the side it would make sense. The Polaris however was probably thrown on by previous owner. Very cool boat though. Get that thing up and running again. It would be a blast!

 

Hello
i put the polaris decal on myself some years ago, i got a non running 93 sl750
then had a shop get the motor running and fiberglass some motor mounts in and rig up a coupler to connect it to the berkley minijet,
i was able to get it on plane and actually had some fun for a few days before i burned a piston down.. despite the vibrations ,they did a horrible job on the coupler!

So now after another 4 years i have the motor fixed up with some racing parts (probably a mistake but live and learn) the coupler is redone the way it should have been and i just have to get the crank seal done to pass the leakdown test,
kinds stuck on the 300$ buddy wants for the job ,for 2 years now lol

i started a thread on GreenhulkPWC to get some help..good people

 

Quick update. We did some work yesterday morning, but are about to get crackin on it again today so I want to keep it short.

Grinded Everything, cleaned with acetone, and masked the holes.




Cut 3 layers of mat.


Laid said mat.










Reinforced the mounts with another 3 layers of chop mat


nearly finished!


Just have to shape the bottom today. Another day we will lay a rib between the stringers where we extended the recessed area for the motor and grind the left stringer to allow clearance near the tuned pipe.

More photos this evening!

 

Geez, man, I can almost smell the resin! Nice work! Thanks for keeping us updated.

 

LOL @ tinhorn. Thank you for following my build...even since day 1, when I was just talking about it.

So we flipped her belly up this morning!


We first had to grind this overhang off, from where we stretched the fleece.


We did that, but forgot to take pics...so for now you will just have to take my word that it turned out B@D@SS!

Then we used these B@D@SS Adjustable flexible longboard Sanders. This is a product that was developed, patented and are now manufactured by one guy in his personal shop. It was just out of coincidence that we met John, the owner of AFS (Adjustable Flexible Sanders).

My bro and I were out to lunch in Cottage Grove, MN when we saw this BADASS sunbeam driving up. To make a long story short, it was John, the owner of AFS. He was happy to tell us about his sunbeam which looked like a fabrication shops demo car that they had spent a year building. It wasn't though. It was a creation of John's with his own 2 hands. Custom widened by a foot, custom turbo set up, chop top with custom cut windshield, roll cage, suspension, custom paint, and on and on...

John told us about his car and the paintjob that he did on it and I was amazed at the lines of the car and the flawless paint. Straightest body I had ever seen. He told me it was all due to his patented invention. He invited to his shop to show us his set up. My jaw was on the floor as he explained how he developed this idea and designed and produced these sanders. I believe he said he sells over 12,000 of these sanders a year that he makes all by himself. I used them today for the first time, and I will be using them throughout the rest of the shaping and fairing.

They are basically longboard sanders in various lengths that can be adjusted by their stiffness to follow any body curve, from straight to even a harsh curve, while still maintaining a perfect smooth curve/line.

We are using these AFS's in these pics below to level out the glass and identify the lows that we would be filling. We also determined how the strakes would be shaped.








Here you can see the gap we have to blend out.




Here we determined our strake point locations on both sides, then pivoted a straight edge from that point to the edge of the jet ski which created a nice arrow shape and blended out the strakes. We also blended out the other minimal gaps with a straight edge as well.








This will all be more apparent once we start sanding, which we are about to do right now. Bye.

 

Purchased some TAP Plastics products to create a waterproof, durable, buildable product to fill gaps and spaces that fiberglass would simply run out of, or areas that chopped mat and resin could not be laid into properly. I purchased their Microspheres, and Chopped Fiberglass.

 

?????

 

So here is the first coat of reinforced filler after it was sanded.
Yo can see the beginning of us forming and extending the strakes forward. This was done this past Sunday.




Last night I laid more reinforced filler and did more shaping with the AFS (Adjustable Flexible Sander)






What do you all think of the shape? I'm no hull design expert. Does this design make sense?