Restoring the Mark 1 to Jet power.

[Pat Ross]

Hang in there Lou, it is looking good!

Pat

[luigisante]

Smooth as a baby's ass. Well, almost. This weekend, I was eating my heart out knowing that 3 hours away the boat show was in full swing but, given the approach of winter, I felt that I had better get this part of my project done and the cabin started before the cold weather sets in. It was in the 30s last night so I guess I was right.

Anyway, the glass work is basically done. You can see that the foresection of the insert is faired. It is amazing how close to the curvature of the hull I was able to maintain.

Fairing completed on the foresection of the insert. Picture is before sanding. Final Insert 3.jpg (3.2 KiB) Viewed 156 times

Once the entire insert was sanded it was very smooth.

After initiail sanding - very smooth. Final Insert 2.jpg (3.27 KiB) Viewed 156 times

Right after taking the last picture, I wet down the whole area to see the imperfections. It is so close that it probably doesn't really need another fairing coat but I am going to go over it with 410 compound, filling only the small minor imperfections so that I can sand it smooth and ready for barrier coat. I would guess that the barrier coat will be done Saturday. I'll probably put a coat of copolymer bottom paint on it to block out the UV from the epoxy.

I spent quite a bit of time checking out the thrust angles (like I could do anything to change them) and they look perfect. I am glad that I lowered the insert in the rear to deflect the thrust angle downward a bit. It looks right.

I've already shifted by morning coffee thinking to the cabin. I'm sending the jet pump out to be rebuilt and to have the higher torque impeller put in. The engine is going to the dealer for a tear down and inspection before installing. This down time will allow me to focus on the cabin for the next few months. I will be very happy to put away the fiberglass tools and take out the carpentry tools.

Lou

P.S. BTW Pat thanks for the words of encouragement.

[trashpad]

Lou,

If this works as well as you hope, you will be getting a lot of emails asking for advice. Can't wait to here how it performs.

[luigisante]

It's exciting to see the fiberglass work comming to an end so that I can start on the engine/pump installation. The rest of the boat is in pretty good shape, except for the cabin, Structurally, however, everything is in place like the new stringers/floor in the main cabin and shower drain in the forepeak. The project inside is simply reconstructing the galley/furniture (which I am keeping light and simple). I am optomistic that I will be installing the jet drive/engine in early spring and will have the boat at the yard to complete the rigging before summer. I expect initial trials in early summer. We'll know more then.

I am encouraged by a couple of improvements in the jet pump that are recent. A new housing is available with no metal in it. All of the aluminum vanes have been replaced with composite ones. The pump housing is all plastic and the impeller will be stainless. I think that this will go a long way to prevent the galvanic problems that the boat had with the original UA drive. I saw the galvanic problem as one of the biggest drawbacks to the jet drive concept for a boat on a mooring because of the possibility of dissimilar metals in the powertrain. I am less concerned today. There is still the issue of marine growth to contend with, which I am giving a lot of thought.

Larry Pullon, the guy that thought up the jet drive grafting concept for small bass boats has a lot of experience with jet drives. I showed him the progress on my project and he says that I am going to be plesantly surprised at the power and control that the engine will give me. He says I will be docking the boat like one of those stunt drivers that parks in a sideslide. We'll see.

I like the idea of keeping the power for the boat inside and the center of gravity low. The newer seadoos are equipped with cleaner running and quieter 4 stroke engines. If this concept works, it would be easy to upgrade the power to a fuel injecetd 4 stroke, which would fit in the same space and probably give me an additioanl 20 hp with a slight weight gain.

We'll know more in late spring - early summer.

Lou G.

[Ron]

He says I will be docking the boat like one of those stunt drivers that parks in a sideslide. We'll see.

I've got a 20 foot SeaDoo jet boat with a 260 hp Merc and 7 or 8 inch impeller. But no rudder. At speed with power on, I can do tight figure 8's all day long at 50+ knots. Remove the power and it's like a log. Cross your fingers and pray. Don't backup unless you absolutely have to. Docks are something to avoid. I have to shut down the motor as I approach a dock to avoid having the engine torque rotate the boat on me. Every action has an equal and opposite reaction, right? The vertically mounted motor rotates one way, the boat the other. Even in neuteral (which involves pulling a cup half-way down over the jet - similar to a PWC). Your rudder will help. Most of my problems are due to having nothing hanging in the water to steer with.

I imagine that your jet is mounted towards the port side and the prop wash does not pass thru the rudder. Can your jet port swivel? If so, I'd try to attach some linkage to the rudder or tiller - like the new 28's. One of the most manueverable boats I've ever used, even with it's 18 foot beam. With its linkage disconnected and centerboard up, it's back to crossing your fingers.

[luigisante]

It is my intention to link the tiller and the jet so that they turn in a coordinated fashion. The jet ski has a linkage that responds to the turning of the ski's handlebars. I think that linkage would be easily converted to transmit turning impulses from the tiller in the same manner. I think that was the way that Tony Smith initially had it on Mark 1's. From the reviews, it looked like the boat was fairly controllable. I'm crossing my fingers. If I hate it, I can always hang an outboard. Here's hoping I don't hate it.

The installation of the seadoo cutout came out well though ... ya think?

Lou G.

[Ron]

The linkage is probably similar to the setup on my SeaDoo jet boat. It's a double cable system, with one pulling from each side. You should be able to build something similar to attach to the tiller or rudder. Take a look at the 28's system. You need a way to easily separate the two when sailing. The tiller shaft is really two concentric shafts - one always connected to the rudder and a 2nd that when pinned to the first, will control the motor. You'll also need a wire based control to raise and lower the reverse cup.

Just note that you will get absolutely no turning assistance from the jet when you throttle down. When it's on you will be able to do circles within your own boat length. It's not that bad - you just have to get used to it.

[Pat Ross]

Lou,

I think the major consideration is the setup for steering is consideration for worse case scenario, loss of steering or uncontrollable steerage, both with and without engine.

Pat

[luigisante]

The biggest problem that the original owner of my Telstar had with the old UA jet drive was corrosion. The old UA drive (circa 1970) contained at least 4 different dissimilar metals. The impeller was stainless, the bearings were bronze, the grates were zink alloy and the housing was a cast white metal aluminum alloy. The parts I had from the old boat were pitted and some were eaten away by electrolisis. You could see where he tried to graft zinks on the parts to protect them, to no avail. When considering wheter or not to try to refit a jet drive, I was most worried about electrolysis.

A small, private seadoo rebuilder in Ohio has suggested a composite pump housing to address the electrolysis concerns.

Composite housing 140pump1.jpg (115.63 KiB) Viewed 122 times

The new pump housing will be completely non-metal, except for stainless bearings and a stainless wear ring (the stainless wear ring almost guarantees a long life and eliminates the possibility of impeller cavitation). Thus, even in salt water, there will be no dissimilar metals to promote corrosion.

I am having the housing fitted with a 17 pitch stainless OEM impeller (capable of producing the highest torque). I think this will solve the electrolysis problem. I am greatly relieved.

The last issue I am concerned about is marine growth. I am, of course, painting the entire assembly below water with antifouling (copolymer) but an concerned that barnacles could grow in the pump housing itself. Anybody have any ideas about how to keep marine growth down on unpainted surfaces? I wonder if the pump housign can be painted with antifouling?

Lou

[Pat Ross]

I haven't got a clue, but this is getting really interesting.

Pat