This just might work,,,,,I hope

[stupidbaker57]

Remember the guy 4 or 5 years ago that put a Honda motorcycle engine in a 3 point hydro and designed a surface drive for it? It's me. Now I've got another brain child to ponder. I have a 9 foot jet ski hull and would be using a Honda civic 4 cly. engine. This is where it gets dicey. I want to drive it with a prop but on a self trimming design. I thought that a prop shaft with a universal joint at the engine and the shaft being mounted to an A shaped arm to allow the shaft to have vertical movement. A spring mounted to the A arm will force it down to 12 or so degrees. When gaining speed a horizontal fin mounted to the shaft tube would force the shaft up to 9 or 10 degrees to allow the prop to break the surface. (surfacing prop needed). The shaft will be over driven by 15 or more percent. Steering will use an outboard mounted rudder. Now that you're done laughing,,,,,I built a bulldozer out of a lawn tractor, and converted a 16 ft outboard boat to V8 stern drive. This sounds doable.

[TNT Teen]

I've often wondered how much faster a jetski could be if it had a surface drive. I'd be very interested to see how this project progresses.

Why self trimming and not a trim system that you control?

[Powerabout]

I've often wondered how much faster a jetski could be if it had a surface drive. I'd be very interested to see how this project progresses.

Why self trimming and not a trim system that you control?
There was a thread on a guy who ran the shaft out the back and had some F1 props on it, doing over 100mph then he stopped posting...hmmmm

[stupidbaker57]

I've often wondered how much faster a jetski could be if it had a surface drive. I'd be very interested to see how this project progresses.

Why self trimming and not a trim system that you control?

No trim pump, no rams, no extra weight, no thinking.

[stupidbaker57]

There was a thread on a guy who ran the shaft out the back and had some F1 props on it, over doing over 100mph then he stopped posting...hmmmm

I think I have a picture of that jet ski. He used 2 rudders and a surfacing prop. The engine, I believe was a jet ski engine.

[kenboyd]

"Those who say it can't be done should stop bothering those that are doing it."

What a joy to finally see those words in print! I have been aware of the painful frustrations caused by the NAYSAYERS most of my 71 years of life.

About your idea? Sounds good. GO FOR IT! I'm looking forward to see it's progress.

I think I saw several videos of the jet ski you are writing about, showing his progress on that project. He was jamming down a river, with a huge rooster tail behind. VERY COOL.

I have been restricted by some major self inflicted injuries, for the past few years, but I am preparing modify my already modified Sport C tunnel hull. https://www.youtube.com/watch?v=dqtSZBS5HzE http://www.boatracingfacts.com/forums/showthread.php?7842-Ken-Boyd-s-Toy&highlight=ken+boyd (Ron Hill four blade clever on that.)

I'm replacing my 1989 70hp Evinrude long shaft fishing engine with a 1976 75hp Johnson Stinger. The steering is going from Teleflex to cable.

[stupidbaker57]

"Those who say it can't be done should stop bothering those that are doing it."

What a joy to finally see those words in print! I have been aware of the painful frustrations caused by the NAYSAYERS most of my 71 years of life.

About your idea? Sounds good. GO FOR IT! I'm looking forward to see it's progress.

I think I saw several videos of the jet ski you are writing about, showing his progress on that project. He was jamming down a river, with a huge rooster tail behind. VERY COOL.

I have been restricted by some major self inflicted injuries, for the past few years, but I am preparing modify my already modified Sport C tunnel hull. https://www.youtube.com/watch?v=dqtSZBS5HzE http://www.boatracingfacts.com/forums/showthread.php?7842-Ken-Boyd-s-Toy&highlight=ken+boyd (Ron Hill four blade clever on that.)

I'm replacing my 1989 70hp Evinrude long shaft fishing engine with a 1976 75hp Johnson Stinger. The steering is going from Teleflex to cable.

It's good to see another master of mayhem (I'm 69) willing to climb in and go! My 11 ft cab over hydro melted the motor too. Couldn't get enough air to it getting on plane. (it was air cooled) I sold it to a couple of young fellas from Maine. I'm still in the cocktail napkin designing stage but I think it will work out OK, I hope.

[Fastjeff57]

I've seen snowmobile motors used, bolted vertically to a tower, but what I've always wanted to run is a rotary engine, say a Mazda two rotor. OMC messed with them years ago and they were fast.

Jeff

[Mr Pete]

Well, you can start with these photos..... ;) The first consideration for our Arneson prototype was a secure housing on the transom, for the CV joint that was water proof.

I don't know if Rik Wimp at Arneson Eng. ( now in Fontana, Ca) knows if a smaller version was ever made? Maybe find a used Borg Warner 'aluminum smallest drive you could modify? My sense is, you want a very small version ... but your idea seems like a fun project.

If you want HP in a small engine, may I suggest you contact Curt Jordan ( Jordan Engineering - Oceanside, Ca). He knows nearly every motorcycle & snow mobile/ jet ski engine, & how to make power, tune it for your needs & exhaust.

[25XS]

Why not just grossly overpower the PWC with a readily available Mercury V6 outboard engine stuffed under the seat?? You keep the stock jetpump so you only have to invent half the project.

http://www.greenhulk.net/forums/showthread.php?t=11389

[Mr Pete]

Good thought .... also get a fire breath'n racing/ cheater jet pump.

[Fastjeff57]

Neat, but I have to ask a question: How fast can a water jet boat go? There has to be some speed restriction on the jet drive sucking in water to blow out the back, right?

Jeff

[Mr Pete]

Uh, honestly, I think you can modify anything to go faster.... BUT.... after that, it's all about the hull & what it can handle.

( I shulda invested in Aeroquip for this project)