A "Do-It-Yourself" Outboard

[Rocket]

A "Do-It-Yourself" Outboard

I think it's fairly safe to assume, that if there was a cheaper, simpler, more efficient way to transmit power from a motor mounted on top of the transom to a prop just below the surface of the water, one of the numerous outboard manufacturers that have existed over the last 110 years would have made a fortune from it.

The only possibility for that title would be the Thai long tailed motors, but the fear of lawers, stops the western world using them in a racing context. http://www.youtube.com/watch?v=mRvVOMPtwiI

Lawers are like unguarded drive belts they both love their pound of flesh.
I find it hard to imaging how guarded belts, pulley wheels & the prop shaft with it's support bearings, could ever be as hydrodynamic as the ugliest fishing lower unit.

Wouldn't the cheapest way to solve this question be to bolt this powerhead onto a used 12 hp leg, machining an adapter plate & a drive shaft adapter & buying a 20 year old leg can't be that expensive.

Hey Mr. Seagull170---I find it is never safe to assume

[seagull170]

Mr Rocket where did I go wrong?

[Slowboat510]

Here's an idea.

Check out the picture of this belt drive, horizontal shaft R/C outboard that was once marketed. It utilizes a belt drive but adds an intermediate shaft. I have no idea what the torque curve is on these engines, but this would give you the ability to gear it down. This would allow a much larger prop selection too.
Check out the gearcase...I mean lower unit! Clean and simple.
Scale it up!
As far as a cowl, all you really need is a spray shield. Keep it simple. It would be so easy to lay up a mold and pop out light weight spray shields.

[Rocket]

"Do-It-Yourself" Outboard

Mr. Seagull
I don't know if you are wrong or right but your first sentence says "it is fairly safe to assume" which I find is not safe at all. I also said there is a cheaper way to power a prop shaft, I did not say it was simple, or efficient and did not say it would be hydrodynamic. You did?? After all we are talking about a 4 cycle lawn mower engine that costs less than a $100.00 and someone that wants to Do it themselves. If you want to use something else go ahead. Also you brought lawyers and pounds of flesh into the equation. I must say that motorcycles and go karts both use belts and chains--with guards--- to race with. I write this in a positive way with a smile on my face as an answer to your question nothing else. I was saying to Mr. Hill he had a good idea and being positive in my reply. I did not seek out an argument, and do not want to be negative. I find a pat on the back is much more acceptable than a punch in the stomach.

[Rocket]

A "Do-It-Yourself" Outboard

Check out the picture of this belt drive, horizontal shaft R/C outboard that was once marketed. It utilizes a belt drive but adds an intermediate shaft. I have no idea what the torque curve is on these engines, but this would give you the ability to gear it down. This would allow a much larger prop selection too.
Check out the gearcase...I mean lower unit! Clean and simple.
Scale it up!
As far as a cowl, all you really need is a spray shield. Keep it simple. It would be so easy to lay up a mold and pop out light weight spray shields.

Now that is a great idea!!!

[Ron Hill]

Back On The Ranch....

As promised, my "BLUE PRINTS" for my Stage II DIY Outboard Racing motor.

Clamps, saddle are pretty much 30-H/55-H copies. I am casting the thumb screw in one piece of stainless steel and will polish the now black plastic part. I think it will look cool.

Probabl going to powercoat the clamps, saddle and tower housing...not sure the color, except white looks good to me.

Cowling will be better looking than my drawing. It will have some carbon fiber showing, and have not settled on a color.......might goo with "Write me a ticket" red.

The electric motor will be brushing 48 volt, the 212 will be rewind starter, and the 414 will be electric.

ALL THREE MOTORS will be sold as racing motors.

I plan three classes:

Varsity Hydro for the Solar Electric

A Hydro Heavy (212 cc)

C Hydro Sit Down (414 cc)...

If you can't figure out my drawing, let me explain it, the best I can:

I plan two pulleys, 30 MM wide) for gear ratio changes. Starting with a 14: 16 ratio. On the middle shaft where the 16 tooth pulley will be, I will also have an 1 3/4 pulley, 30 MM wide. In the gearcase I will have the same 1 3/4 pulley. The gearcase will split like the OMC 15A gearcase.

All pulleys and belts will be sealed up in the mid section and gearcase.

Will it work? Sure. Can I sell any? MAYBE!

[Ron Hill]

Thanks....

Check out the picture of this belt drive, horizontal shaft R/C outboard that was once marketed. It utilizes a belt drive but adds an intermediate shaft. I have no idea what the torque curve is on these engines, but this would give you the ability to gear it down. This would allow a much larger prop selection too.
Check out the gearcase...I mean lower unit! Clean and simple.
Scale it up!
As far as a cowl, all you really need is a spray shield. Keep it simple. It would be so easy to lay up a mold and pop out light weight spray shields.

We have our polishing shop three blocks from our shop, as that is as close to the dirt that we want to be. We opened the shop 3 1/2 years ago. The business next door builds RC boats.

He build 8 a week, 50 weeks a year. 400 boats a year, all for wet eater motors. He build these boat for many manufacturers. The boats are almost as big as a current J Hydro....

People buy the hulls, assemble the parts in their garage and they are off to the races...


Chad and my dad built this Weedeater Outboard: http://www.boatracingfacts.com/forum...eater+outboard Chad was 7, this was 27 years ago!

[Ron Hill]

Weed Eater Outboard

http://www.boatracingfacts.com/forum...utboard&page=9

Gen III has a clutch.....worked *****en.

We played with these til Chad turned 9, and we went into J Runabout racing....

[walleye]

Outstanding Ron. Interested in what the final product would cost. At 40mph maybe a future J stock replacement. Bobs Karting sells the Box Stock Project motor shown in the attachment for $295.95. These motors weigh about 35lbs.
Also they build them at a separate factory than the lawn mower versions and work hand in hand with AKRA on improvements and tolerances. And they are extremely dependable, racing 100 lap races including yellow flags.






TACH]27691[/ATTACH]

[Danny Pigott]

Clone

This motor is taking over Karting ,They are selling them as fast as they get them cost is $99.00 to 125.oo depending on who you get it from . It takes a kit it to make it run,, pipe, top plate with throttle fuel pump ,air filter about $100.00 They had a Kart race tn SC last week paying $10,000 to win in this motors class had 106 entries in the class. Good luck Ron i think it will work.

[Ron Hill]

Danny and Walleye...

My point, which probably was missed by most people (In my above posts), was that when Chad was 7, we built outboards out of our Weed Eater. Today, one shop that I know about, builds 8 boats a week, 48 inches long or longer for Weed Eater motors. Or another way of looking at these "HOMEMADE BOATS" is 400 a year get built, from one shop. I fell well could have 400 new boat racers a year from a DIY Outboard

My goal is a DIY Outboard for under $1,000. The BELTS AND PULLEYS COST LESS THANT $60 BUCKS. (McMasters-Carr) Gears for this size motor can cost $600.

I was at Cook's Corner and of the 400 Harley's there, more than half had belt drives.....

My thoughts were: Time to get off our collective asses!


ADD:

Danny, I don't know you but have read every word you posted on BRF. Your are a "DAVEY CROCKETT" type, like me.


Walleye: We could build a inboard boat like the RC's...Great motors...


Thank you both for not thinking I fell off the turnip truck....

[Rocket]

A "Do-It-Yourself" Outboard

Hey Ron
I agree with the whole idea about a DIY outboard and have some parts already fabricated. I would really like to help with your project --- what can I do??
Skeet

[walleye]

Ron; I've always admired your work and ideas. I think there's alot of other people that feel the same way. The racers that reject your ideas feel threatened. We both know the 2 cycle outboards will always be the premier classes, I could see a couple of these motors on used boats sitting in the pits with $1,500.00 price tags on them. Send a couple J drivers out during intermission for a demonstration run. Mayby it would bring new people into the sport. People keep saying the economy is killing the sport. I started attending boat races in the late 60's and it was huge. Yet nobody had any money back then. You were there and you know why. I't was OK to have an old boat on top of the old stationwagen. Keep it up Ron!
Like Rocket said, I'm behind you. Down in Florida in case you need support here. I'll be at the Stock Winternationals taking pictures in the pits. Frank

[RKO]

I'm working on a project and one of the alternate my versions has some simularities. Instead of a jack shaft in the tower did you consider using idler pulleys to guide the belt into the bullet and on the propshaft? Belts are the way to go. I never liked the 10% loss with gears.

[Dave M]

Belt Drive

I have long thought a belt drive would be a great way to go. Much less expensive to repair than gears. And you could do it between heats if you chewed up a belt. Hard to replace a gearbox between heats.

I always wondered if a snowmobile type clutch would create the ultimate belt drive system for an outboard.

Ron - FYI - I have more money in my mud motor rig for waterfowl hunting than I do in my best Super E Hydro. Those things are not cheap. The Black Death surface drive I would like is 12K for just the engine. I have a 35 Kohler Surface drive now, those are around 10K. Maybe a little less depending on what brand you get.