3.3M Mini Jet Boat Build

Joined
Apr 9, 2016
Likes
40
Location
Mi
#1
I've been at this build for a while. I figure people here might be interested and I can always use advise on things.
I bought a 3.3m hull kit from RSRacecraft.com and a 1996 WaveVenture 1100. The plan is to put the too together and make a stout small boat for jamming around.

The first few posts will get things up to speed as I have been working on it a lot already.

The kit comes with all the hull panels cut and bent. Thats it. The rest is up to you to figure out. You have to muscle it into place and weld it all up. I did 99% of this alone so i had to get very creative with rigging stuff. Here are a few pics of the lower hull coming together.
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This is a ASP cast intake and cast grate with steel bars inserted. The main goal is takeing this boat where boats dont go. Strength and keeping rocks out will be key. The stock yamaha pump tunnel got tossed out. I made a ring to weld into the hull. The pump tunnel then mounts to the ring and the grate to the tunnel.

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Joined
Apr 9, 2016
Likes
40
Location
Mi
#2
The full pump assembly mocked up using the ASP intake and all the yamaha 155mm stuff
I had to make an adapter plate to fit the yamaha midshaft housing to the intake. I later found that using a kawi style bearing setup would be way easier but I was already committed to the yamaha stuff. I back calculated the driveshaft length and JetManiac cut and resplined it for me.
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I sandwitched the transom between the pump tunnel and pump. I had to machine the sealing lip off the impeller ring to flush it up to the transom. Luckily I thought of that before getting the shaft shortened. I will use high strength marine adhesive for final assembly.
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Getting the sides on was a major step in making it look like a boat.
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Here you can see the adapter behind the midshaft block to adapt the bolt pattern.
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Mock up of the wind screen and fore deck. That fore deck got slowly forced into place starting at the back. It was amazing to see it all flex into place like the kit said it would.
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Joined
Apr 9, 2016
Likes
40
Location
Mi
#3
Underside of the fordeck with bracing so I can jump on it.

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My over complicated bow eye.
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Closing gaps was a regular pain. I put straps and jacks to use many times during the welding process. Here I am forcing a warp in the transom out into the rear step so I can tack it all upon the other side.

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Lots and lots of welding and grinding went into this photo. ..... Lots
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Joined
Apr 9, 2016
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40
Location
Mi
#4
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The Yamaha 1100 comes with the electronics and everything mounted to itself. Its a nice drop in unit but I found in racing many relocated it off the engine. I may do the same someday. Also it didnt have the best fuel pump setup but for now im staying stock.
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I had to cut the WaveVenture waterbox up to shorten it for packaging so I used some of the left over materials to make an exhaust mount. Also used the WaveVenture straps and stuff.

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Stock WaveVenture exhaust tip had to be flipped 90deg to fit but I think its going to work ok.
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Joined
Apr 9, 2016
Likes
40
Location
Mi
#7
Does anyone know if my pump is compatible with the newer Yamaha reverse gates and mounts? I'm wondering if I bought a reduction nozzle and steering nozzle from a newer sitter with the big reverse gate if it would fit up.
 
Joined
Aug 16, 2011
Likes
112
Location
cape may, nj
#8
The newer skis that used the 155mm pumps reverse gate won’t work unless you fab up some bracketry. With the way your work looks like. I don’t see you having a problem making it work. Are you wanting to switch bc it’s plastic? With being wider it does divert the water better. There’s a company called Cobra Fins. They make these pieces that bolt on to the steering nozzle to help with the steering. Also if you were looking to separate the electronics from the engine, can’t you switch to the 1200 npv? It’s the same footprint just like the 700’s n 760’s. The 1200 has bigger cylinders and bigger carbs. I use to work on a lot of Yamaha exciter jetboats. The 1200 motor ones hauled butt. The 220hp 1100’s were far behind. Thing I didn’t like was getting to the electronics bc it was tight against the bulkhead. If you don’t have that issue I wouldn’t try to switch it to a 1200 style.
 
Joined
Jun 6, 2015
Likes
101
Location
Tennessee
#11
I have always wanted to do this, I have a part you need. It’s the steering piece off a wetjet. What the bars would mount to that converts it to a steering cable. Pay for shipping and its yours. I’ll take a pic cause I’m not sure what the real name for the part would be.
 
Joined
Apr 9, 2016
Likes
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Location
Mi
#12
ChrisRacerX:
The stock wave venture reverse setup is nearly useless. If there isnt a easy bolt on upgrade I will probably just build or buy a better duel exit gate and make it fit. I agree that 1200 engines were better but I figured 1100 would push it around pretty good and I found one cheap locally. I may do a GP1200 intake and carb swap in the future or just drop in a 1200 assuming the mounting is similar.

Joe Dart:
I had planned to machine a simple steering column or something until I saw Teleflex JBS steering helms. Currently the plan is to use the JBS helm and cable. The Waveventure cable was to short and the steering post would have needed too much modification than it was worth. I am still up for other ideas. Show me what you have. Might be a better option.

I am also looking for a steering nozzle for the wave venture pump. Mine is badly worn. I can weld it and re drill but if a good one is cheap ill jump on it.
 
Joined
Aug 16, 2011
Likes
112
Location
cape may, nj
#13
Gotcha, yeah the 1100 would be fine with what your doing. I agree on the reverse gates being a little hard to use. On the skis and thing that didn’t help was the ventures and wr3’s that had reverse were flat bottom. The ski didn’t know which way to go. Try a gate from a xl800 or 1200 PV models or any of the 4 strokes. Thoses cobra fins will help though with the steering in reverese also help steer when you throttle down and there is no thrust. They are basically little skegs attaches to the steering nozzle
 

smoofers

Rockin' the SQUARE!!!!
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Joined
Sep 30, 2007
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586
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Granbury, TX
#20
This is ridiculously cool AF!!! Excellent work. Can't wait to see more updates!
 
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