A "Do-It-Yourself" Outboard

[Ron Hill]

Keep Thinking Positive

When the war ended, my dad and brother went to work to build my brother an "A" Motor. Later, Orlando Torganti won five straight NOA and APBA Natonal Championships with dad and brother's lower units.

As a family we didn't have the money to attend National events, but we stayed positive that we could race locally. My brother dated Orlando's daughter.

Keep it positive, "BACK YARD" people are the heart of this nation and always has been.

I've "Imaged" or "Dreamed" of having 10-20 boats lined up, all motors running, and when the flag drop, putting the hammer down. The clutch would engage and the race would be on.

I recently heard, that the newer SEA-DOOS have brakes and interesting concept.

You may or may not have notice my orange flag on my "Sit Down" C Hydro.My thoughts, if each boat had a flag with your number on it, it would be easier to score, and also you could see the flag above the spray....

I am aware the MUD MOTOR CAN be EXPENSIVE, but they can also be cheap.

Most hunter don't buy the $10,000 MOTOR FIRST. Dave Rankin (Wild Child Super Stock) serious big time racer in Region 12, started out in a Sport C. Fred Bowden started racing a Johnson 150 in MOD VP. When Fred quit racing he had 153 propellers, 8-S3000 motors, 6 boats, and $100,000 transporter.

My hope is other will see my design and improve it, work on their own. I'm not doing it to make money. BUT,maybe someone could turn the DIY Concept into a money maker.

The weather has been too cold for ME to go testing, but I've decide my cavitation plate is too wide, (See picture), I'm going to make a new "Gearcase" without a cavitation plate. Also, I think I need a fur blade or at least a three blade prop,


The YELLOW area on the cav plate, might catch in the corners, in a straight line, no problem.

[walleye]

Yes, adding the clutch would make beach starts more practical. Also entering the pits. Good safety items, not to mention 3 minutes of milling time eliminated from the program each heat.

[seagull170]

Ron how much "push" do you expect from 12.5 hp?
Are we talking 200lb +, pillow blocks are not all that good at a side load, it might need a tapered roller (wheel type bearing) at the front & a ball race at the prop end.
Do we have a mechanical engineering graduate on here that can work out the side thrusts on all these bearings from the belt loading?
You will also have to check if the crankshaft main bearing on the power output side is man enough for the additional loads.

[Ron Hill]

Run Stuff Til It Busts

I usually run stuff till it busts. My son, Chad, when I can get him to talk about this project, said I need a wheel bearing in the nose. On the dual belt drive, I'm going to have a tapered bearing.

I'm really a PROP MAN and I usually fix things with a BIG HAMMER!!!

[seagull170]

$200 motors don't tend to be built for anything more than was intended.
When the belt that connects the jack to the crankshaft is passing 12.5 hp on towards the prop there will be a significant downwards pull on the crankshaft, this load will be directly proportional to the diameter of the crank pulley (I'm fairly certain).
If these motors are anything like the Briggs & Stratton my lawn mower had, crankshaft running in diecast ally crankcase, their life expectancy might be measured in hours not days.
Find a graduate that can do the calcs & I'll be real happy to be told I'm talking rubbish.

[Ron Hill]

All Graduates I Know About Are Occupying Something...

I know there is a ton of these motors running on go carts!

If they don't last, we could make a billet case with ball bearings. AND actually build anew crank....We need to just run them and see what happens.

http://www.youtube.com/watch?v=sZUtv...e_gdata_player This guy goes 31 MPH on a 14 foot John Boat. This is where I got my idea, I made the prop.

[seagull170]

Do carts run gearboxes? because gearbox output shafts run in bearings designed to handle the chain loads.

[matthias]

I really like the idea of using these motors in a boat. I would be more inclined to do a conventional inboard hydro with the motor up front. A clutch basket could be coupled to the shaft.

[Larry Darneille]

Bring back the small inboard. This could be the new crosley!

[Rocket]

A "Do-It-Yourself" Outboard

Ron
You don't need a tapered roller bearing for the hosepower/thrust you are going to make---take a look at a 5 Litre inboard propshaft bearing they last for years and have a ton more thrust force than a little clone motor and a light boat. The bearing is held in place with set screws and basically the same as what you have in your pictures. The clone engines that are being run on karts make 15hp very easy and last for a long long time--the crankshaft is very strong and the block is built to handle more than what you are proposing I have even seen one with a blower on it. Strength and power are not a problem just the DIY and the cheap part

[ricochet112]

$200 motors don't tend to be built for anything more than was intended.
When the belt that connects the jack to the crankshaft is passing 12.5 hp on towards the prop there will be a significant downwards pull on the crankshaft, this load will be directly proportional to the diameter of the crank pulley (I'm fairly certain).
If these motors are anything like the Briggs & Stratton my lawn mower had, crankshaft running in diecast ally crankcase, their life expectancy might be measured in hours not days.
Find a graduate that can do the calcs & I'll be real happy to be told I'm talking rubbish.

It's common to see ball bearings on the PTO end of the crank in these engines, but not always. Most of the cheap Chinese knock offs coppying Honda will do like Honda and have ball bearings on the PTO shaft (vs the mag end of the crank, really heavy duty engines have dual ball bearings, PTO and mag end). Many other cheap parts to fail before the PTO bearing...

Just look at an IPL of the model and serial # and it will tell you.

[walleye]

As stated previously these clone engines have revitalised kart racing and are used in about 90% of all classes. Pull up Inox lubracants 100. This years race using these engines is $50,000 payout. $25,000 to win. Do you really believe there junk. The other engine engine used is the Briggs and Stratton Animal. Pull up Briggs and Stratton Animal and there is a lot of info on them. They can be had for $455.00, usually run methanol. All these engines bolt up the same.

[scotindallas]

how about like this?

Here is a concept. Maybe using 3/8 aluminum plate.

I know the propshaft will be off center to th skeg but any thoughts of issues?

the pic is rotated so the angled end would be the bottom of the skeg

[ricochet112]

As stated previously these clone engines have revitalised kart racing and are used in about 90% of all classes. Pull up Inox lubracants 100. This years race using these engines is $50,000 payout. $25,000 to win. Do you really believe there junk. The other engine engine used is the Briggs and Stratton Animal. Pull up Briggs and Stratton Animal and there is a lot of info on them. They can be had for $455.00, usually run methanol. All these engines bolt up the same.

The cheap Chinese knock off engines I refer to are the ones like Ron bought at Harbor Freight for $99.

[walleye]

I showed the Briggs as a comparison. The Box Stock Project engine is the yellow honda clone I posted previously. They can be bought thru about 30 different sources. Thats what most classes use now. They have accumulated hundreds of thousands of miles and have proved to be durable. I have a Honda on my shop floor. Nobody uses them.
I just saw a Cadillac roll out the door of a GM plant in China on the news. Every time I see one now I'll be thinking Cadi knockoff. I'm being sarcastic of course.