Jet Boat conversion... Ideas??

[Guyph_01]

Hi guys,

Well as some of you know im getting my ski fixed and will soon have my first ever ride on a jet ski Also that i have purchased a Jet boat as spare parts so i had parts to get one engine rebuilt.

I thus have this complete boat that i'm thinking or installing an Outboard engine on it.
First thing is what size Hp outboard engine would suit it? i'm thinking between 40-60??
Also i'll need to build a transom that will support the new engine. An ideas?

This it what i have come up with

Now, as you can see from the pics and my great Professional Paint drawing, the base is 15 1/2 inch. How high would the engine need to sit if the third drawing is the new transom?, i.e how high should the red question mark need to be?

I know its a jet ski forum but i just thought i'd ask. I'm happy to gather as much ideas, thoughts as i can get and this will allow me to apply the best solution to the problem

 

[Sink]

Just a thought but wouldn't a used rotax cost less than an outboard and all the mods needed to fit it?

 

[Guyph_01]

In The US yes, but not in Australia. I just got the engine off that boat rebuilt for my jet ski and its gonna cost me around $2500. More than twice what you guys pay for a rebuilt engine. Outboards here i could get a old but reliable one for maybe about 400-600. And the fiber glass work might cost about 200-300 i think.

 

[LouDoo]

Something you will want to consider before you do any work is the shape of the tube. Obviously from you picture it's holding air. But once you loose the tube you probably won't find another one, it's a pretty rare boat.

Lou

 

[Guyph_01]

Loose the tube? What do you mean? I want to keep it, without it the boat will sink.
Not sure what you mean.

 

[LouDoo]

Once the tube is no longer useable, when it won't hold air any more. I meant lose the tube.

Lou

 

[RFoster130]

Yeah the explorers are hard to come by. I would bet you could sell the parts and buy a decent project boat that would be better in the end.

 

[Guyph_01]

Once the tube is no longer useable, when it won't hold air any more. I meant lose the tube.

Lou

When does that happen? Only when its gets holes, rips etc? Can't that normally be fixed? Doesn't the tubes last a lifetime? Or are they terminal?
Hummm maybe i should try and see how well it holds air before i do anything else.

 

[Guyph_01]

Yeah the explorers are hard to come by. I would bet you could sell the parts and buy a decent project boat that would be better in the end.

Well the engine off that boat is going to be used in my jet ski. all the seats trim have been eaten buy the sun. What parts are worth $$?

And thx guys for the thoughts, I would have went and bought fiber glass materials before even thinking of checking if the hold air tubes? Any other thoughts?

 

[Guyph_01]

Hi guys, I found some leaks and want to fix it. Been on youtube "how to" and feel confidant that i can fix it. However i need to know if the tubes are made of PVC or Hyperlon to buy the right glue/patches etc... Does anybody know?
Thx

 

[LouDoo]

I got this from the service manual, tube material: hypalon neoprene, polyester reinforced.

Lou

 

[Guyph_01]

Cool thx

 

[crisso]

Tubes can be redone in poly or aluminium.Not cheap.you will spend over a grand to build a pod to take the outboard.MINIMUM!Transom height will be what outboard you buy.Buy a short shaft model.They are a standard height the world over.Some boat makers have bolt on pods for their own boats.especially alloy boat builders.Ring them.The boarding platform will be the biggest drama.To make it half decent.About 50hp min.Whats the other skis in front of the boat?

 

[LouDoo]

Outboards in Oz must me considerably cheaper than here. You'll need a fairly modern outboard or it's going to weigh a ton. Here it would cost $1200.00 and up.

Lou

 

[Guyph_01]

Crisso, Those are the two ski's of 1MACGYVER. He helped me find the boat so i would have all the parts to rebuilt my Jet ski engine.
What do you mean "you will spend over a grand to build a pod to take the outboard.MINIMUM!" my idea was to built something in wood that i would bolt to the boat. then lay fiberglass over it and fuze it to the existing fiberglass. I was thinking a 30-40hp engine. You recon that won't be enough? The idea is to be able to pull a wakeboard, knee board, tube etc with max two people in the boat. What would you suggest and how should i build the transom?

Lou, Hummm didn't think or that weight, good point, i'll keep that in mind. Yeah they are much cheaper

Would be cool if i actually build this thing

 

[Guyph_01]

Also Guys, I would love to be able to keep the fuel tank and gauge, and speedo and the third i think is the tacho. But most importantly the fuel gauge and speedo. It seems that i'll be using the control elec box in my ski. So is there a way of getting the fuel gauge and speedo wired up to work?

Also at the moment there fuel in the tank. How can i get it out? Engine has been removed from the hull.

Also, how do i remove the center console? I'm trying to get all parts off like the revers handle cable etc. I've located the 4 nut and bolts that hold it to the hull but when i put the spanner on the nut, both the nut and bolt turn:S

Thx

 

[LouDoo]

You probably can keep the speedometer and fuel gauge, usually (depending on the year) they wiring runs through the MPEM, however you should be able to connect them up directly to their sensors. I recently connected a speedometer to my 96GSX without going through the MPEM, here's the thread. You'll need to download the service manual and a wiring diagram.

http://www.seadooforum.com/showthread.php?46640-Has-anyone-got-any-idea-how-the-speedo-sensors-work

Since most outboards in the HP range you want are three cylinder you probably won't be able to use the SeaDoo tach., but you can get an aftermarket one line the Trail Tech.

You'll need to siphon or pump the old fuel out of the tank, I have an old electric fuel pump, just connect it to the reserve nipple on the fuel baffle.

As far as removing the center console, I don't know, Explorers are really rare, I've never actually seen one, only pictures. If the whole bolt is turning you could try using liquid wrench or PB Blaster, you may need to cut the bolts and re-epoxy new ones to the hull. Does it tell you how in the service manual?

Good luck, it sounds you you'll need it.

Lou

 

[Guyph_01]

Nope the manual does explain how to separate that part. So what i done before night fell i removed the top cluster cover thing. Now i can see the head of the bolts and will need a meter long extension to reach them. Also think i may need two people do undo them. Tomorrow will tell. Anyway only taking everything at the moment until i figure out if the tube are viable. I've bought some patch kit and starting to patch it up lol. I hope i do it good
Extra parts i'll put up for sale on ebay

 

[LouDoo]

It's very possible that the console is not made to separate from the hull. Decks on PWC's cannot be separated from the hull except by cutting them apart.

Lou

 

[Guyph_01]

Ok little update.

I have patched all the holes that i was able to find on the tube when it was still attached to the fiberglass hull. Have to wait 36hrs before i can inflate it and figure out if they are fixed or if these more Should be easier since the tube is off.

Also i was able to unbolt all the parts that won't be needed if i ever do the conversion without removing that center console. It was annoying but its done.

Only thing now is how do i remove the steering and reverse cable from the back of the hull near the pump? from inside or outside?

Shame i won't be able to keep the steering handle etc. I though of keeping it but it doesn't turn enough i think

Also gave the inside and outside of the hull a good clean and wash down as this didn't cost more than time an effort. Apart from the perished trim on the seats, i must say it does look very good.

 

[Guyph_01]

Found quite a few leaks This is taking for ever!!! not only does it take hours finding the leaks, prepping, cutting the patches, gluing and then the 36hr wait before i can inflate it to test again and find new or missed leaks and start over again:S but hopefully i'll be able to patch it all up

 

[crisso]

Hey Guyph.To do want you want to do you will need at least 50hp.Any smaller and it wouldnt pull a stick out of a dogs clacker.You would be revving the crap out of the motor all day.
With the mount for the outboard.I would recommend getting one made up from aluminium plate and where it bolts to the boat,reinforcing those areas.Much easier and it would look a heap better.Stronger also

 

[crisso]

I forgot to add.You will also need to cover the jet intake area underneath the transom otherwise the outboard will be running in unclean water and you will have a heap of cavitation problems.An alloy plate cut the same size as the intake grate would be smple

 

[LouDoo]

Guyph,

Since it looks like you're serious about this project, what about a small inboard or a small inboard/outboard. I tend to agree with Criss about the outboard, a 50HP with all the extra rigging is going to put too much weight at the stern of the boat. I would think it's really going to screw up the geometry of the boat.

With an inboard you would put the weight close to where the original motor was, and also you would need far less fiberglas work. I'm thinking something like a four cylinder mercruiser inboard/outboard.

Lou

 

[SabrToothSqrl]

I think it would be easier to just find a small working boat...

but good luck! that thing is funny looking w/out the air bags around it.

I always thought the one where the jet ski could dock / undock from the back was neat and james bond like...