Anyone here run mini jet boats?

[ABMax24]

Who here runs one? What kind of places have you been, what setup do you run and what would you do again or do different? Pictures are highly encouraged.

The reason I ask is after countless hours of research I have decided to build a 13' boat with 3/8" center section, and a 2' strip of UHMW. It will be powered by a 2007 Seadoo RXP 215 motor and pump, and hope to see the hull within the next month to begin fitting it out.

 

[J-Roc]

Interested to see how this pans out. Got a few buddies with them. One is an Eagle hull and the other was bought from the states. The eagle is running the supercharged sea doo while the other is runing an 800 Yamaha. Both work well but I haven't been around for any fun.

Who is building your hull?

 

[neilsleder]

I been looking at those to. I been looking at buying the plans from Cope boats out of Vancouver. I would build my own just to say that I did. I thought that I would try to find a seadoo that had a wrecked haul but they are not easy to find. I hope people post some pics.


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[ABMax24]

Interested to see how this pans out. Got a few buddies with them. One is an Eagle hull and the other was bought from the states. The eagle is running the supercharged sea doo while the other is runing an 800 Yamaha. Both work well but I haven't been around for any fun.

Who is building your hull?

Bratt jet is going to build the hull. They built a 12.5 ft with a 260 kawi and was running 70mph, so I'm hoping for 55-60.

I been looking at those to. I been looking at buying the plans from Cope boats out of Vancouver. I would build my own just to say that I did. I thought that I would try to find a seadoo that had a wrecked haul but they are not easy to find. I hope people post some pics.


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They aren't easy to findn I ended up going to kelowna to buy a complete running unit for mine.

 

[Bnorth]

Post up a build thread, I consider these things the ATV's of the boat world. Great for hitting up the ultra skinny rivers and creeks. I don't have one but would love to build one someday.

 

[deaner]

Ive always thought a used turbo apex would be the perfect donor for one of these things. With a decent water to air system you could run some big power on pump fuel, and you can pick them up for pennies on the dollar now.

 

[Bnorth]

Ive always thought a used turbo apex would be the perfect donor for one of these things. With a decent water to air system you could run some big power on pump fuel, and you can pick them up for pennies on the dollar now.

I've thought the same thing, I think the biggest issue would be mating it to a jet pump with the taper fit crank.

 

[ABMax24]

I've thought the same thing, I think the biggest issue would be mating it to a jet pump with the taper fit crank.

Not to mention the huge amount of underhood heat associated with a non-marinized motor, plus I think there are kits available that can push the seadoo motors past the 300hp mark, although I think 215 should be enough for me lol.

 

[J-Roc]

Not to mention the huge amount of underhood heat associated with a non-marinized motor, plus I think there are kits available that can push the seadoo motors past the 300hp mark, although I think 215 should be enough for me lol.

You'd have to run abelt drive I think in order to get the rpm right. I've been thinking on this as well.

 

[ABMax24]

You'd have to run abelt drive I think in order to get the rpm right. I've been thinking on this as well.

Iirc the motors are geared down to something like 8000 rpm for the belt drives in sleds so that shouldn't be a problem, as the new seadoos are turning 8100 rpm, and my 07 turns 7650 rpm. That would hopefully be one less hurdle to avoid.

 

[NoBrakes!]

The exhaust manifold would be the only piece that needs to be "marinized", I'm sure a someone could build you a water jacketed or water injected manifold. Not sure which pump you would use on the Apex project, maybe a small berkeley 6J? The tapered output shaft to splined input shaft might need a bit of thought but could be done. Not sure how the motors are "geared down" but in a direct drive scenario, I believe the rpm limiting factor would be impeller size no? thoughts? Any way you go it will be a great little boat, Kevin and the boys at BrattJet do awesome work!

 

[ABMax24]

The exhaust manifold would be the only piece that needs to be "marinized", I'm sure a someone could build you a water jacketed or water injected manifold. Not sure which pump you would use on the Apex project, maybe a small berkeley 6J? The tapered output shaft to splined input shaft might need a bit of thought but could be done. Not sure how the motors are "geared down" but in a direct drive scenario, I believe the rpm limiting factor would be impeller size no? thoughts? Any way you go it will be a great little boat, Kevin and the boys at BrattJet do awesome work!

The crankshaft on an apex is geared down before the primary as the motors spins too fast for a primary clutch. This brings it down to a range useable by a seadoo pump, I would use one of these due to the fact that most boatbuilders have an intake for these pumps. Now obviously if you use a pump intended for a V6 or V8 the output shaft of an apex motor will still be spinning too fast.

I chose the seadoo pump setup for simpicity of making it work with minimal modification.

 

[neilsleder]

I watched a YouTube video of a r1 (apex) powered boat it worked pretty good. But I read the comments and there was some jet boat guys commenting on how that motor revs to high to make a good jet boat motor. I here that Subaru motors are working good for those jet boats.


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[neilsleder]

These are the designs I been looking at.


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[NoBrakes!]

I believe Outlaw Eagle Maunfacturing has an intake and an aluminum suction piece for their sea-doo setups. Post the progress pics please

 

[ABMax24]

These are the designs I been looking at.


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I think those cope designs would be good boats, I just wanted something a little bigger, plus I wanted to have it running for this season, and it for sure wouldn't happen having to weld the hull together.

I believe Outlaw Eagle Maunfacturing has an intake and an aluminum suction piece for their sea-doo setups. Post the progress pics please

Both eagle and brattjet make their own intakes for the pwc pumps, brattjet is going to build me one. I'll try to start a build thread when I start on it, just been busy building the trailer as of lately.

 

[neilsleder]

I think those cope designs would be good boats, I just wanted something a little bigger, plus I wanted to have it running for this season, and it for sure wouldn't happen having to weld the hull together.



Both eagle and brattjet make their own intakes for the pwc pumps, brattjet is going to build me one. I'll try to start a build thread when I start on it, just been busy building the trailer as of lately.

They got a 14' one to. But like you said you want it for this season. For me it's just a pipe dream for now lol. I am going to keep an eye open for a wrecked seadoo.


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[mur190]

I had a 12ft weldcraft with a 120HP Sport jet, worked alright but had a hard time getting parts for the pre XR2 sport jet. Would love to build a mini but it would be somthing like what BWC builds. Full Window with a small drop bow, basically a mini version of the Outlaw Lynx or Firefish Piranha.

 

[ABMax24]

They got a 14' one to. But like you said you want it for this season. For me it's just a pipe dream for now lol. I am going to keep an eye open for a wrecked seadoo.


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http://www.minijetboatbuilder.com/ also sells hull plans and even cut and bent sheets, he used to be out of Red Deer but is now out of Ottawa, and I believe he got started working at Firefish.

 

[ABMax24]

Here's my build thread: https://www.snowandmud.com/boats-and-watercraft/99844-13-mini-boat-build.html#post2145862