Crazy Idea for jet powered boat

[Brian 26]

Re: Crazy Idea for jet powered boat

How much should I expect to pick one up for with such damage?

Way too many variables to give an exact answer on that but I will say the cheapest you'll EVER find a running driving 4tec is about 2-3k. Shooting from the hip....A new engine is probably about $3-4K so I would think a smashed hull with a good motor is worth about $1500-2k.

 

[IDoSeaDoo]

Re: Crazy Idea for jet powered boat

I don't think the neon motor would have enough torque but tuned right it just might work. I don't know the layout of the Seadoo engines and pumps but most Jets have the motor directly connected to the driveshaft via a coupling at the flywheel and the driveshaft directly to the jet pump. A chain drive wont work or handle the torque without some major worries of reliability. I have had a worn chain come off my bike at just 30mph and lock up the rear wheel. That chain will be moving extremely fast and if ti comes loose will put a large hole in the boat very quickly. I would find a way to mount the motor so the driveshaft mounts to the flywheel and directly drives the jet even if you have to custom make a shorter driveshaft. Regardiung the O2 sensors if you are custom making a water jacketed exhaust then make an area for the O2 sensor so that you can use it. You might be able to use another Chrysler marine starter I can not remember if the starter on the neon was unique to it or the standard mopar design/mounting flange. Using the closed cooling system would be good then you just need to mount raw water pump to cool the coolant through a heat exchanger. You can make any marine alternator work. The ignition is distributor less so as long as you have good wires that should not be a problem. Just realize that it would not be CG approved and it is possible you could get cited for not having CG approved equipment. It's not likely unless your drawing attention to yourself but it is possible. All in all I say go for it as long as you don't make any non-reversible changes you dont hurt anything and just waste some time for an experiment. The world was built on experiments.

And that remark that jet boats died out in the 70's is a false statement I am part of a Texas group where jet boats are quite strong. Are they inefficient yes but they have developed and are better than they were. There are races where Jetboats are raced so died out in the 70's don't think so. There are ineffiencies with any boat propulsion system, props have prop slip, jets have basically the same thing just their prop is internal and not external where it can catch on rocks, limbs (both tree and human) among other things.

Even if I am somehow able to reduce the oil pan volume and drop the motor a few inches, I still don't think it would line up with where the stock driveshaft comes in. I didn't think about the chain coming off... that is a scary thought. If it gets wrapped around the running engine, it potentially could saw a hole in the hull (GULP!).

I am gravitating more and more toward the idea of buying a wrecked one from a salvage company. This will in all honesty be a more sure way to go, as all the marinized components are already there. These engines will have less torque as they're less CC and one less cylinder. But it will be easier to implement. I plan on cutting the bottom of the jet ski hull out and mating it into my boat, so that the engine, mounts and driveline are already in place. It's crazy how much these companies want for a wrecked ski. I'm seeing no less that $2k! And I can't assure how WELL (if at all) the unit runs until I pick it up. Yikes!!

 

[Brian 26]

Re: Crazy Idea for jet powered boat

I agree on the prices but I'd take it one step further and say it's crazy how much they want for a new ski. $9k for a seadoo GTI which is a pretty plane jane ski and that is without a trailer!

 

[jbcurt00]

Re: Crazy Idea for jet powered boat

And that remark that jet boats died out in the 70's is a false statement I am part of a Texas group where jet boats are quite strong. Are they inefficient yes but they have developed and are better than they were. There are races where Jetboats are raced so died out in the 70's don't think so.

I think 73 misunderstood Bondo's died in the 70's comment:

Same reasons the ole V8 Jets died in the '70s,...

OUT OF WIDE SPREAD MASS PRODUCTION in the 70's, even Glastron made a few:

Perhaps still very alive in the vintage jet boat racing, river running, or other markets for condition specific applications.

Do the new jet boats that are an out growth of the JetSki/SeaDoo market come w/ V-8's, particularly BIG blocks?

 

[IDoSeaDoo]

Re: Crazy Idea for jet powered boat

That is a GORGEOUS boat, but damn, what a waste of bow space! And no, today's jet boats don't come with big blocks, instead they have twin supercharged engines, producing up to a combined 510hp. Unfortunately, I'm not in the market for something that drinks fuel out of a fire hose YET. I just want to be out there and NOT have all these classic seadoo issues. I got 99 problems, and they're all boat related.

 

[Brian 26]

Re: Crazy Idea for jet powered boat

My friend (who does this for a living) just bought an '07 motor with 123 hours for $2k so I'd say the prices you're seeing are on track.

 

[Brian 26]

Re: Crazy Idea for jet powered boat

Do the new jet boats that are an out growth of the JetSki/SeaDoo market come w/ V-8's, particularly BIG blocks?

No they're just made with the exact same motor and pump they put in the skis. Some are as tame as a 15' boat with the 155 HP single motor. An inline 3 cylinder in seadoo's case. There 15' model is kind of like a big jet ski.

 

[bajaunderground]

Re: Crazy Idea for jet powered boat

I'd look on copart.com (salvaged and other auction site) they have a few Seadoo's, not sure where you're located or the exact motors, but you'd probably know what motors came with each?

SEADOO

 

[IDoSeaDoo]

Re: Crazy Idea for jet powered boat

I actually am looking on Copart, but you wouldn't believe how hard they make it to purchase these things. I'm not sure how much the bidding brings the price up, but even starting out, it's almost cheaper to buy off Craigslist. There are websites like SearchTempest that will comb all the craigslist listings in the nation for what you're looking for. Amazing deals out there! Right now, I'm looking at spending no more than $2k. Hell, at this rate, I might even buy a few skis to ride for next year

 

[73Chrysler105]

Re: Crazy Idea for jet powered boat

Use a site called statewidelist.com it will search all craigslist posts in a selected state and organize them by areas.

 

[Pale Rider]

Re: Crazy Idea for jet powered boat

are you the same dude on seadooforums?

 

[IDoSeaDoo]

Re: Crazy Idea for jet powered boat

The one and only, hey Pale Rider! Also, I use SearchTempest. It searches the entire united states craigslist adds starting with the closest cities to my area code. This idea has settled on me putting a seadoo 4tec in the boat. I actually found a guy in Germany who successfully installed a 215 in a 1997 Seadoo SPX. That's the famous X4 hull that many still lust after. The X4 has the same driveline configuration and dimensions as the X4, so if he could stuff that motor into that ski, I should be able to do likewise in this boat. I also figured, if I'm going to do all this work, I might as well make it jaw dropping. Hence I'm looking for a supercharged donor ski. I'm looking for a 215, but a 185 might have to do as money doesn't grow on any of the trees in MY back yard.

 

[Brian 26]

Re: Crazy Idea for jet powered boat

I actually found a guy in Germany who successfully installed a 215 in a 1997 Seadoo SPX.

Do you have a link for that? Would love to read about it -although I'm not sure how I feel about ripping out a 787....looking at you IDOSeaDoo.......

 

[IDoSeaDoo]

Re: Crazy Idea for jet powered boat

Well, I haven't really begun yet, hence I'm on the forums trying to get any advice. My biggest concern is with the pump. I am not sure that that little 140mm can't deliver the proper amount of thrust to push that boat like I want it to. It would be nice to replace it with the 155mm pump that all the new skis use. The concern comes from the pump intake channel carved into the bottom of the hull. I wonder if it needs to be widened to feed a larger pump... I wonder what it's dimensions are on the larger, more powerful boats. What are the consequences of keeping it small? I've seen guys put more powerful motors into the 96XPs, which have the exact same driveline dimensions as my boat. I wonder if they did any pump intake mods...

What do you guys think, if I increased my horsepower from 110hp from a 2cyl 2 stroke, to 130 or 155hp from a 3cyl 4 stroke, could I still make use of the 140mm pump? What if I increased the prop pitch? I can also increase the pump volume with a spacer (I even have a tall prop for that setup). It would surely simplify the driveshaft issue!

My hypothesis is that it really doesn't matter, that having a narrower intake channel would just suck the boat down more, and also make it VERY important to have a good driveshaft and ride-plate seals. With the increase in suction, there will be increased likelihood of cavitation if there are any pin holes anywhere.

Everything else seems pretty self-explanatory. Once I saw that it was possible to put a 4tec into a 96XP, I know that it can be done in my boat.