FireFish Convict 17 foot 6.2 212 fuel burn.

skegpro

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No I never did, work slowed down and I wasn't going to finance it to pay for it.

Here's a couple videos of them though, they can practically run on wet rocks. It's still the boat I want, except I'd get a window boat with a full engine cover and rear bench seat.



Found this, wonder what $$$ ballpark they would be nowadays.

I assume this was with a sport jet.
Any idea what a new PPI rotax package is worth?
Screenshot_20210703-211227.jpg
 

skegpro

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ABMax24

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That's how I would set one up.

The only downfall to the Rotax engine is the carbon seal on the driveshaft, sometimes all it takes is a little piece of grit to get the seal to leak and then you either have to reface the carbon or replace it, and requires pulling the pump to get to it, and I think on these piranhas the exhaust needs to be pulled as well.
 

neilsleder

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That's how I would set one up.

The only downfall to the Rotax engine is the carbon seal on the driveshaft, sometimes all it takes is a little piece of grit to get the seal to leak and then you either have to reface the carbon or replace it, and requires pulling the pump to get to it, and I think on these piranhas the exhaust needs to be pulled as well.

I rebuilt a couple impellers for them now. IMO they to small little issues become big issues. Like the boat wouldn’t get on step with 28thou clearance. Then the thrust bearing with out of the stator and allied the driveshaft push on the crank. Which then took the crank thrust bearings out which also took out the case halves. Then some how broke the oil pump shaft that totally finished the motor off. Now buddy is looking at $9000 dollar bill because of bad stator bearings! Now granted I think the builder must have put the motor in wrong. But personally am not sold on that rotax.
 

ABMax24

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I rebuilt a couple impellers for them now. IMO they to small little issues become big issues. Like the boat wouldn’t get on step with 28thou clearance. Then the thrust bearing with out of the stator and allied the driveshaft push on the crank. Which then took the crank thrust bearings out which also took out the case halves. Then some how broke the oil pump shaft that totally finished the motor off. Now buddy is looking at $9000 dollar bill because of bad stator bearings! Now granted I think the builder must have put the motor in wrong. But personally am not sold on that rotax.

There is preventative maintenance needed on these pumps, IMO the pump should be pulled at least yearly to check wear ring clearances and the pump cone MUST be removed at that time to check for water intrusion and the condition of the bearings, the grease will turn black once operated with water in the bearings, at that point it's time to replace the seals, bearings, and o-rings. If I use my mini lots I usually check the pump twice a season, it really doesn't take more than an hour to do, and only an extra half hour to swap the wear ring if needed, but so far in 6 years my bearings haven't had a drop of water in them. I still run plastic wear rings, because they are cheaper to replace/rebuild than the stainless impeller. Yes the pump requires fairly tight tolerances, but 28 thou and not getting on step sounds like air intrusion into the pump, or the intake grate is too restrictive.

I can't recall what the exact specs are for the pump alignment and in particular the axial play on the driveshaft, but I can grab move driveshaft and move it forward and back a little, which should protect the motor if the pump thrust bearing failed. I'm not sure the details on that failure, but if it was me the builder would have some explaining to do.

I get why some are leary of these powertrains, but there are literally hundreds of thousands of these things out there in boats and seadoos across North America. With the end of the sportjet, this is the only option for a light weight, low cost jet drive.
 

NoBrakes!

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ya but they're mostly in a rigid OEM install... an aluminum jet boats flexes constantly and the pump angle gets changed over and over as you hit ch!t.... they're light weight
 

ABMax24

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ya but they're mostly in a rigid OEM install... an aluminum jet boats flexes constantly and the pump angle gets changed over and over as you hit ch!t.... they're light weight

Absolutely, but the driveshaft has crown splines and can accept some movement, and enough axial play in the shaft allows for flexing of the hull as well.

There definitely is room for improvement in the driveshaft design, I'd like to see a proper water seal on the shaft, but every aftermarket design for the Seadoos I've seen can fail, and instead of weeping water into the hull like a carbon seal they typically tear the rubber boot and pour water into the hull.
 

NoBrakes!

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look at the cleetus video with his and the 300... hes gonna be the guy to get this ch!t made properly. him and finnegan will change jet boating... you watch.

minis need a proper 6" pump built. period.
 

ABMax24

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look at the cleetus video with his and the 300... hes gonna be the guy to get this ch!t made properly. him and finnegan will change jet boating... you watch.

minis need a proper 6" pump built. period.

I've seen some of his videos, so far there's nothing revolutionary about his mini.

We'll agree to disagree on this point. Run a proper intake grate on the pumps and they do well, Cleetus has way too large of openings in his grate for these pumps.
 

NoBrakes!

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who else has a 2020 300 in their mini? come on man, he's a beauty and he's got contacts. oh and that billet blower wheel and tune? I have buddies with Jetstreams... One is 100% TIG welded.... and they're not like those two. lol
 

ABMax24

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300hp in a mini has been around for at least the last 6 years, brattjet built a 300hp kawi powered mini about 6 years ago. Bigger supercharger wheels, bigger injectors, and high hp tunes have been around on the 4tec motors since 2004, the guys that want lots of power are pulling the superchargers and going turbo.

Like I said, he hasn't done anything revolutionary yet, "oh but it's a 2020" lmfao.

Here's a turbo Kawi from 2016:

 

NoBrakes!

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dude... you're a mini guy, we get it..... this thread is about a 6.2 212 in a big boy boat lol

proper grate? look at a Hamilton grate... the axial is made to move junk... except these ones? because they're lightweight plastic junk....

next we are going to start talking about making a Spark cool....
 

ABMax24

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dude... you're a mini guy, we get it..... this thread is about a 6.2 212 in a big boy boat lol

proper grate? look at a Hamilton grate... the axial is made to move junk... except these ones? because they're lightweight plastic junk....

next we are going to start talking about making a Spark cool....

Just answering questions and correcting inaccurate information.

You're the one trying to talk sh!t about something you have no experience with.
 

neilsleder

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There is preventative maintenance needed on these pumps, IMO the pump should be pulled at least yearly to check wear ring clearances and the pump cone MUST be removed at that time to check for water intrusion and the condition of the bearings, the grease will turn black once operated with water in the bearings, at that point it's time to replace the seals, bearings, and o-rings. If I use my mini lots I usually check the pump twice a season, it really doesn't take more than an hour to do, and only an extra half hour to swap the wear ring if needed, but so far in 6 years my bearings haven't had a drop of water in them. I still run plastic wear rings, because they are cheaper to replace/rebuild than the stainless impeller. Yes the pump requires fairly tight tolerances, but 28 thou and not getting on step sounds like air intrusion into the pump, or the intake grate is too restrictive.

I can't recall what the exact specs are for the pump alignment and in particular the axial play on the driveshaft, but I can grab move driveshaft and move it forward and back a little, which should protect the motor if the pump thrust bearing failed. I'm not sure the details on that failure, but if it was me the builder would have some explaining to do.

I get why some are leary of these powertrains, but there are literally hundreds of thousands of these things out there in boats and seadoos across North America. With the end of the sportjet, this is the only option for a light weight, low cost jet drive.

This was less than 40hrs on a rebuilt impeller, new seals new bearings. But yah I think the builders didn’t put enough end play, I think he should stick to turbos for sleds and not boats. But they’re just not meant for gravel and pumping trash they spin to fast. And sand up easily. Chris and I know a guy that has one it over heats do to sand and wrecks impellers pretty much every time out.
IMG_0229.jpg

Here’s a sport jet compared to the heavy duty PPI rotax motor and pump combo. That right there explains why I am not sold on that
 

neilsleder

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And that PPI rotax impeller got wrecked in one weekend at about 15hrs. I rebuilt it tighter and used 2209 duplex rod and then got 40hrs out of it.
 

ABMax24

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This was less than 40hrs on a rebuilt impeller, new seals new bearings. But yah I think the builders didn’t put enough end play, I think he should stick to turbos for sleds and not boats. But they’re just not meant for gravel and pumping trash they spin to fast. And sand up easily. Chris and I know a guy that has one it over heats do to sand and wrecks impellers pretty much every time out.

That's what I have found, the gravel has to be kept out of the pump, but once that is done they work well. I trashed my first impeller in under 20hrs, but my grate also had 5/8" openings. My new grate the opening are between 5/16" and 3/8", if I were to do it again I'd add an extra bar or 2 and bring that down to between 1/4" to 5/16", but this works well for now, my current impeller has over 100hrs on it and there are only a few nicks on the leading edges. Maybe I'm just not as hard on equipment as some guys, but I've never had an issue with sand in the heat exchanger either, but I've also opened up the cooling system for more flow, so maybe that's why?

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