Glen-L.com

Hello all,

Just signed up for the forum. I wanted to know if anyone had done a jet drive on the flying saucer. I would like to keep the twin cockpit, put the steering wheel on the front right seat, and use a 500-750cc jet ski motor. In order to achieve this I would like to lengthen it by 10% and try to keep the cockpits the same size as the original design. What would I have to modify on the transom, floor, etc to make this happen? Is this a feasible idea? Thanks for your time and I look forward to becoming a more active member on this forum (this is my first post).

Thanks,

--Matt--

I'm no boat design expert, and I've only just begun my first build, but my previous boat was a jet boat, so that makes me an expert!

Seriously though, the one issue I see with a modification like this is that you'd have to blow a hole through the keel a couple feet forward of the transom, essentially "breaking" the keel. I'd imagine you'd need to create sufficient reinforcements to compensate for the split keel, otherwise that would seem like a dangerous stress point to me. But again, I'm no expert (i lied earlier )

What about using a jet-drive outboard engine?

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Jeff

My Celerity build.

Here is how one building modified a squirt keel with the engine in the center
http://www.glen-l.com/picboards/picboar ... 1164a.html

The glen-l facebook page has a picture of a Zip with twin jetski engines. Here is the engine compartment. https://www.facebook.com/#!/photo.php?f ... =1&theater

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http://picasaweb.google.com/vupilot/Chr ... O0x7SvsQE#

"Nothing screams poor craftsmanship like wrinkles in your duct tape."

jprice, what do you mean by a jet drive outboard? not familiar with that style of engine.

I just chose that particular arrangement because of its availability (plenty of 500-750cc jet skis available under a grand in this area) and compact design.

Vu, thanks for the pics. If you have any more of the hull like that of the squirt please post them up. I don't know enough about the jet drive system to design it on my own but living on a shallow pond as I do (a lot of it is 3' deep or so) I decided on the jet drive system to be able to use it there, it being more elevated than conventional outboard design. I could realistically use an inboard motor of another design but jet drive makes it that much more unique.

We have some info for using a jetski in our website:
http://glen-l.com/jet-jon/

There's also a jetski section on this Forum:
http://www.glen-l.com/phpBB2/viewforum.php?f=23

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Gayle Brantuk
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Glen-L Marine
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Your issue is going to be having enough room. The ski setup will be a minimum of 40 inches long - most are longer. I can't remember the exact length of my drivetrain but I can measure tomorrow if you still want to know.

At a 10% stretch, you're at 13 1/2 feet. The rear cockpit will be taken up by engine and pump leaving you with not enough room for 2 cockpits. It would be a really nice single cockpit. But I don't see any way to keep both cockpits with a jet drive.

When I laid out the cockpit of my 1st boat, I used masking tape on the garage floor (its still there). That might be a good exercise before you make your final decision.

Good luck,

KB

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"I'm not trying to get it perfect. I'm trying to get it finished!"
Squirt Build: http://www.tubbytug.com/SquirtHome.html

That would be a big help if you wouldn't mind measuring.

Does anyone know how long the factory transom/engine mount is? Meaning the back of the rear seat to the transom? Like I was saying I was expecting to keep the cockpits the same size just move them forward (or add the 10% behind the rear seats only). I know this moves the center of gravity forward when people are in the passenger area but my hope is that the weight of the ski system being greater than a conventional outboard will help to keep the weight balance where it should be. I don't want something that nosedives when the power is suddenly taken away, but I also don't want so much weight near the transom that it gets swamped when the power is shut off as well.

It's basically an outboard with jet propulsion at the bottom instead of a prop.
http://www.yamaha-motor.com/outboard/fe ... _2006.aspx

_________________
Jeff

My Celerity build.

I am using the same setup as bulldog and my drive train measures about 34-35" from the front of the motor the back of the pump (which will mount on the transom). I wouldnt rely on my word 100% though since I have yet to actually install the motor.

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Why not is why!

Sweet. I guess all I really need to know to find out if it's practical or not is what the dimension is for the flying saucer--anyone have that? (transom to rear seat, approx.)

I like the jet drive outboard as an option if this doesn't work out, provided that is shallower than a conventional short shaft outboard.

I've also been toying with the idea of lengthening it as I described and putting the engine in between the two rear seats. I need to see what the width is of one of the jet ski engines first but I believe they're narrow enough to still have a reasonable sized seat on either side of a motor box (think of the design of the inboard Ski King but with the motor box moved back between the rear seats instead of in front of it). I just don't know what the rear cockpit size is so I'm not sure if that would work or not.

Forgot if I asked this or not, but what's the width of a conventional jet drive motor at its widest point (in the front of the engine)?

Thanks,

--Matt--

Bump, does anyone have those dimensions? I would rather not waste the money on the plans for the flying saucer if the setup is too long and would make the rear seats too narrow to be usable with a motor box in the middle of the rear section.

Thanks,

--Matt--

It may be a little too much engine or weight, but the sport-jet set-up used in lots of small14' jet boats like the Bayliner Jazz and Sea Ray F-14 has the engine sitting over the pump and would probably fit in the area you want on the F-S and for sure the Zip.....probably better suited for the Zip.

Mercury Marine doesn't have the specs on their site for the old 90HP sport jet pkg, but there are lots of those to be had used in the $1-2,000 range for a running donor boat

I've always been surprised that someone hasn't used one of these to build a jet Zip

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Remember,if you buy a pkg like this, you get steering fuel tank, gauges,trailer,lights,etc...lot's of stuff you could use in the build that you'd have to buy later, so a $2,000 price might actually be cheaper in the long run.


Some examples:
http://tampa.craigslist.org/hil/boa/2604574421.html

http://tampa.craigslist.org/hil/boa/2637088128.html

http://cgi.ebay.com/ebaymotors/1993-sea ... 415dff6567

http://cgi.ebay.com/ebaymotors/SeaRay-S ... 4aaf4fa2c1

http://cgi.ebay.com/ebaymotors/SUGAR-SA ... 45fd8cd63f

This is the pump unit that the powerhead sits on top of:

http://cgi.ebay.com/ebaymotors/Mercury- ... 588ff07da4

This is the powerhead that sits on top of the pump:

http://cgi.ebay.com/ebaymotors/Mercury- ... 3cba693190

_________________
Boat building can best be defined as an endless series of
tragedies obscured by the occasional miracle, followed by a good bottle of beer.

Don't Dream Your Life, Live Your Dream

The issue with the width will not be the motor itself as the motors are fairly narrow. The issue will be everything that bolts to the motor. You will have a carburetor or two on one side and an exhaust on the other. I am out of town until Monday but will measure then. I don't want to whiz on your parade but I do not think the things you want to do will fit. I will measure and you can decide. Its just math.

KB

_________________
"I'm not trying to get it perfect. I'm trying to get it finished!"
Squirt Build: http://www.tubbytug.com/SquirtHome.html