Dyno Jet

About using jet ski motors to power small boats

Moderator: Bill Edmundson

FFR
Posts: 1
Joined: Thu Jul 17, 2008 1:00 pm
Location: Aliquippa Pennsylvania

Dyno Jet

Post by FFR » Thu Jul 17, 2008 10:32 pm

Hello,

I have a line on a 650cc Jet Ski motor. My son and I would like to build
a Dyno Jet. I built a Picklefork some years ago.
My question is: Stich and Glue contruction. The photos I have seen
show the hull being built before the framing. Is this a simple
construction method compared to framing first? I am not a woodworker
by trade or hobby. The Picklefork turned out OK, but could have been better. I want this projct to be out A1. Any advice would appreciated

Sincerely,

Doug and James

User avatar
leakcheck
Posts: 2950
Joined: Mon Nov 17, 2003 3:01 pm
Location: Lander Wyoming

Post by leakcheck » Fri Jul 18, 2008 4:58 am

Doug and James,

You will get some great answers here as a few have built the Dyno Jet.

I hope to one day build it as well, I have a Yamaha 701 motor already.

From everything I have read the Stitch and Glue method is much easier and much much quicker than building on frame.

Look through some of the pictures and wait a couple of days and some of the Dyno Jet guys will chime in...if not...PM them and they will surely share their knowledge with you.

We love pictures so keep us posted !!

Steve :wink:

DanH
Posts: 538
Joined: Tue Nov 25, 2003 1:33 pm
Location: Norfolk, Massachusetts
Contact:

Post by DanH » Fri Jul 18, 2008 7:57 am

Stitch and glue is a fast and forgiving building method compared to plywood on frame. The hull shape is defined by the careful bending of panels and not a preconstructed frame.

marksa1458
Posts: 166
Joined: Mon Sep 12, 2005 5:57 am
Location: Massachusetts
Contact:

Post by marksa1458 » Sat Jul 19, 2008 12:10 pm

I built with the stitch & glue method. It is amazing how quickly a few pieces of wood look like a boat. But... there is nothing quick about building a boat. I remember bringing the wood home in the spring and thinking I would be finished by summer's end. It took me about 3 years to "finish" my boat (not quite done, still fine tuning)

The Dyno Jet is a great little boat - if you are still in the "planning" stages, you may want to consider a Seadoo drive train. You only have about 42" of engine room and most of the vintage Kawasakis are around 55" You can use a driveshaft out of a Kawasaki TS to shorten things up considerably. Many folks hang a large portion of the drive train out of the back, but I think this may lead to porposing and poor performance. I have a SeaDoo SP and the drive train looks like it would fit in better ( you will have some engine alignment work that you don't really have with the Kawasaki set up.. Also, the thruhull on the Seadoo is a bit more forgiving than the Kawasaki)

Good Luck...
Both the below websites detail my build progress.

http://dynojet.fateback.com/Index.htm
or
http://www.geocities.com/marksa1458/

Scott
Posts: 308
Joined: Sun Sep 17, 2006 3:21 pm
Location: Canada, Southern Ontario

Sea Doo

Post by Scott » Sat Jul 19, 2008 8:41 pm

You would probably want to go for the Rotax model 947 DI. Same technology as Mercury Optimax's for the direct fuel injection which comes from Orbital. You have the reed valves that you can switch to carbon reeds and it weighs less.

951ccm
135hp
2 stroke DI
2 Cylinder
Thun.der.bolt
ˈTHəndərˌbōlt

A flash of lightning with a simultaneous crash of thunder.

An ignition system of early Mercury outboards that not only is a nightmare to diagnose but also improves a marine mechanics competency.

slociviccoupe
Posts: 31
Joined: Tue Jun 09, 2009 11:08 am
Location: Palm Bay Fl.

Re: Dyno Jet

Post by slociviccoupe » Tue Jun 09, 2009 5:59 pm

I am planning on a dynojet with a rotax 951 engine out of a xp limited. the silver engine. Just deciding what pump I am going to use. I have 2 140mm pumps which are all aluminum, but could get the bronze 155mm pump from the ski the motor is from. Or there is even a better pump from the new supercharged sea doo's. it is 10 veins and 155mm impeller diameter.
I would love to run the di setup as mentioned as there are an abundance of these engines available. but not a lot of boat shops around here have anything good to say about them in ski's.

I have a question though about the dynojet construction. Would it be possible to build the hull out of thinner plywood like 1/32 or 1/16" plywood. then use more layers of glass in the construction. Essentially the wood would just be a surface to atach the glass to and form its shape?
This is my first boat Im attempting to build. Ive had jet ski's and they get old after a while. think that a little 2 seat boat with jet drive would be fun.

wwamann
Posts: 24
Joined: Fri May 01, 2009 2:55 pm
Location: Freeport Florida

Re: Dyno Jet

Post by wwamann » Wed Jun 10, 2009 10:33 am

Just a question.

Why would you want thinner wood and more layers of fiberglass ?

Waren

slociviccoupe
Posts: 31
Joined: Tue Jun 09, 2009 11:08 am
Location: Palm Bay Fl.

Re: Dyno Jet

Post by slociviccoupe » Wed Jun 10, 2009 11:01 am

Honestly I do not know, I am new to boat building. Although I used to work at Sea Ray Boats in merrit island florida. I have more experiance with fiberglass than i do with wood. Figured the wood would be easier to work with if it was thinner. The wood would create the shape of the hull and the glass would be the strength.
Also, With the availability of a cnc router could the bulkheads be made one piece instead of multiple pieces joined and bolted together? Im not sure If im going to build the dynojet or a tnt. But definately going to be using the seadoo pump and engine combination. Not sure for a first boat if wood over frame or stitch and glue would be better for me. I do have experiance working with wood as I worked at an aircraft company building wood wings for airplanes. Just hope that some of the experiance will cross over to boatbuilding.

wwamann
Posts: 24
Joined: Fri May 01, 2009 2:55 pm
Location: Freeport Florida

Re: Dyno Jet

Post by wwamann » Thu Jun 11, 2009 6:54 am

I'm under the impression that the frames give you the shape, the plywood (in designed thickness) gives strength and the fiberglass/epoxy gives you waterproofing / abrasion resistance.

That wood is lighter than the same thickness of fiberglass/epoxy

while working with thinner sheets would be easier, you would still be required to achieve the design thickness of the hull by laminating additional sheets on the hull.

Also I read that plywood frames do not work well, especially if fastening to the edges.

I think that while some bulkheads are attached to or are part of a structural frame ,some are nothing more than compartment dividers with no real structural function.

Having never built a boat (being a retired submarine sailor i've been around a lot in various stages of completion) i'm just going on my own research.

There is a lot in information on this site/forum so make sure you read both the archived and new post and look at all the pictures (worth a thousand words each)

Waren

slociviccoupe
Posts: 31
Joined: Tue Jun 09, 2009 11:08 am
Location: Palm Bay Fl.

Re: Dyno Jet

Post by slociviccoupe » Thu Jun 11, 2009 8:07 am

Thanks for the reply, I did not know that wood was lighter than the same thickness of fiberglass. I finally decided on a pump setup with the help of a jet ski builder on the internet. Since I will be using a 951cc rotax it is best for me to match it to the pump that the ski came with. So I will be running the 155mm pump. But, most the 155mm pumps are plastic with a bronze insert. Yes less weight and no corrosion, but not desirable. Come to find out the 97-1/2 gtx limited had an aluminum pump with a bronze insert that is 155mm. This pump is very hard to find. So I will be going with the seadoo rxp pump from their new supercharged jet ski models. It is a 155mm pump, with a bonus. It has 10 stator veins stock instead of the common 6. More veins help straighten the water flow.
So since im having to run a bigger pump with the larger displacement engine, I have to find a gsx or gtx limited that ran the 951 engine with a 155mm pump. That way I can graft the section out of the jet ski hull for the pump and engine mounts into my boat.

slociviccoupe
Posts: 31
Joined: Tue Jun 09, 2009 11:08 am
Location: Palm Bay Fl.

Re: Dyno Jet

Post by slociviccoupe » Sat Jun 13, 2009 10:00 pm

for finishing the boat, anyone have any knowledge if it would be possible to gellcoat over the glassed surface.

User avatar
Bill Edmundson
Posts: 11597
Joined: Wed Nov 23, 2005 6:45 am
Location: Birmingham, AL, USA
Contact:

Re: Dyno Jet

Post by Bill Edmundson » Sun Jun 14, 2009 5:34 am

By the time you have glassed the boat, added two or three coats of epoxy to fill the weave and sanded it smooth, you can gell-coat or paint what ever you want.

Bill
Mini -Tug, KH Tahoe 19 & Bartender 24 - There can be no miracle recoveries without first screwing up.
Tahoe 19 Build

slociviccoupe
Posts: 31
Joined: Tue Jun 09, 2009 11:08 am
Location: Palm Bay Fl.

Re: Dyno Jet

Post by slociviccoupe » Sun Jun 14, 2009 11:34 am

I just figured that jet ski's are gell coated. Gell coat is a little more forgiving than paint. That the gellcoat could be applied directly over the glass and resin without having to use the high build primer. Then there wouldn't have to be the decision of what paint to use below the waterline because gellcoat is meant for that. The gellcoat can be sanded smooth just like the high build primer. Then would be painted with automotive paint base/ clearcoat.

Just recently I just picked up the hull of a 99 seadoo gtx limited. Hull Had a 951cc engine in it with a 155mm pump. So I have the perfect starting point for grafting it into my hull. Will be getting engine parts shortly. will be building a 1050 big bore motor using the 10 vein seadoo rxp metal pump. Whats nice with the rxp pump is it will match the engine I am building, it has the vts trim system and also has a reverse bucket.
I will be using the steering dystem from the jet ski and machining an adapter to put a small steering wheel on it.

upspirate

Re: Dyno Jet

Post by upspirate » Sun Jun 14, 2009 1:52 pm

Sounds good.

Have you checked out Bulldog boaters site on grafting the ski hull into the build?

http://www.tubbytug.com/SquirtHome.html

slociviccoupe
Posts: 31
Joined: Tue Jun 09, 2009 11:08 am
Location: Palm Bay Fl.

Re: Dyno Jet

Post by slociviccoupe » Sun Jun 14, 2009 2:36 pm

Ive checked out most of the jet ski based builds on this site. I have to say thumbs up to everyone who has a boat out on the water.
I think Im going to stretch the hull to 12'. I would also like to do something different than others and the forward deck integrate the jet ski hood infront of the driver and passenger. This will also give me a spot to mount my gauges. i may use either 2 hoods cut down to fit, or take 2 hoods cut them in half and glass in a center section. I would like this to be able to lift up on hinges kind of like a hatch. As for the rear hatch Im wanting to make it have smoother lines from the deck. Also thinking of integrating in a fiberglass scoop like those on offshore powerboats. Place this in the center to aid in engine cooling. And It will add some looks to the boat also. Not sure what I will be doing for seats as of yet. Might be taking a fiberglass go kart seat and having it upholstered. I just want a boat that is capable of 70mph which my engine pump combination is capable of, something i can take out anytime, and something that draws attention and gets looks from everyone.

Post Reply

Return to “Jet Ski Power”