The dependable eska

[The-Machinist]

I was tired of working on my brothers little ted willams 5 hp so I made him this for his birthday.
He says he couldnt be happier with the performance, and his fuel consumption was cut in half.
Total cost, $46 not counting the briggs&stratton.

 

[fishrdan]

Re: The dependable eska

Cool, and it's a 4-stroke to boot!

How many HP is the engine, what did it come off of? (the neighbor isn't going to be pissed when he goes to mow the lawn is he )

I would love to see the inspector's reaction to that out in California on their "4-stroke only" lakes.

 

[The-Machinist]

Re: The dependable eska

The motor is a 6hp that came off of a terribly underpowered airens riding mower that was given to me. I am currently building a 8hp version using an old sea-king 7.5hp. This one will have a folding tiller and a twist throttle. Not to mention foward and reverse. People seem to like this and it has gotten a lot of attention. Makes me glad I applied for the patent

 

[The-Machinist]

Re: The dependable eska

Of course, if I were converting omc or mercs I would probably be hung by my thumbs from the yardarm

 

[F_R]

Re: The dependable eska

Not ot mention that Briggs & Stratton already builds an outboard. Now about that patent.......

 

[CATransplant]

Re: The dependable eska

That's a clean looking conversion. One question: How did you couple the B&S shaft to the driveshaft on the outboard leg?

 

[The-Machinist]

Re: The dependable eska

This is the coupler I used to connect the shafts. http://www.grainger.com/Grainger/items/3ZN70
I picked up the same item from my local machine supply store for less $. I discovered later that they sell a coupler that is 1"idX1-1/8id that would not have required as much machining
I had to turn down the eska coupling on the lathe and cut a keyway using the milling machine. The two piece coupling simply clamps over the turned down eska part.
The patent applied for covers the "bracket assembly for the conversion of 2 stroke outboards to 4 stroke by way of engine replacement". The brand of replacement engine was not specified.
Thanks for all the input, I have had multiple requests to "convert" other outboards. Maybe Im on to something here?

 

[Oregon Boater]

Re: The dependable eska

Nice job
I was pondering if it was possible awhile back when I was having trouble getting my 7.5 to run.
I remember my father in-law ,who passed some years ago, used to have a small outboard that just used a lawn mower engine of some sort.
Wished I had it today.

 

[mckeemm]

Re: The dependable eska

Hi Guys,

I'm thinking of a similar conversion to an 55 Johnson 5.5 with a blown power head. I can pick up a new 6.5 hp briggs from the local surplus warehouse for under $100.

Question: What is involved in making the throtle /governor linkage work with the twist grip throttle. Does the governor portion need to be taken out of the equasion in order to get a decent idle speed and full range throttle? I imagine a cable can be rigged to the twist grip.

Mohawk

 

[Capt Ron]

Re: The dependable eska

I've been bouncing this idea around in my head for a couple of months and not surprized to see it done. This thread is over a year old and I usually don't look that far back for ideas, thanks for bumping it up.

My plan calls for cutting the splined section off the two stroke crankshaft and welding it to a machined hub. The new crankshaft would need to be shortened, and a keyway cut. I'd machine the motor mount/adapter from aluminum since I run in saltwater.

One more thing I'd like to do is route the exhaust down to the original housing for under water exit.

Now here's the rub: SC law states that any outboard motor 5hp or more must be titled and display a registration sticker on the cowling. I'll have to call and get an official determination on repowering a 4hp non-titled motor to a 6.5hp unit. I'm not sure if there is a "homebuilt" catagory.

Capt Ron

 

[1946Zephyr]

Re: The dependable eska

Cool job on the conversion. I have to agree, that you will have a good reliable motor. I've always thought about doing that myself. I have found that those B&S motors are very co-operative and easy to run and do well even after neglect.

 

[mckeemm]

Re: The dependable eska

Hey Capt Ron,

Several others have done these conversions. Lots do what you are thinking and chop the end off the old crank to make the adapter. I suppose if the old crank is toast then it's no loss. I may try to save the old crank as it is a good spare otherwise. I was also thinking of running the exhaust in the leg for the "water muffler" effect. I would also use an aluminum adapter for ease of workability and weight.

No requirement for outboard tittles here in Ontario. You could always get some 3.5 hp decals for your 6.5 hp motor

 

[Capt Ron]

Re: The dependable eska

Has anyone reported the difference in weight between the 2st and the 4st engines? I don't want to build something that is going to be hard to handle. My back is not in the best shape, nor my wallet.

Another idea I have is to use the motor and controller from a golf cart. The motors usually attach directly to the axle with a short splined shaft, however there is no bearing housing or bearing on the splined end of the motor. This would have to be fabricated. The throttle can be nothing more than a 5k ohm variable resistor. Add 3-12v batteries and this would provideat least an hour or two of quiet, vibration free power. Wouldn't it be great if the drive shaft and armature splines matched. The motor on my Club Car is a 3.2hp and feel that it would out run a 3hp gasser since the electric can out rev the gasser.

Capt Ron

 

[mckeemm]

Re: The dependable eska

Capt.

I have also thought of going the electric OB route. The golf cart would be a good source of components, but unless you have these bits on hand or can find them free or for little cost there's not much incentive. By the time you cobbled it together and bought three batteries you would equal the cost of a decent 2-stroke troller or store bought electric.

I just picked up a free 3.5 hp Briggs vertical on a rolling lawn mower body. The flywheel had partially sheared the key so it was a non-runner but an easy fix. I'll try and get it going and see what I can make out of it.

Mohawk

 

[Capt Ron]

Re: The dependable eska

I have been given such components in the past but like a lot of stuff, they got passed on after awhile. While the cost of buying all new components may be beyond my means (like my other future project of converting an S-10 to electric) the ease of operation, quiet ride, and lack of maintenence make the idea attractive.

Besides, I like putting together oddball things that make people say "Hey that's sharp"... The for sale sign goes up immediately. Also, in this day, Greenies will snap up anything that's earth friendly.

There are companies making electric boats and outboard motors already and yes they are expensive.

Capt Ron

 

[mat_man22]

Re: The dependable eska

I have 3 hp Sears/Eska that I am considering repowering with 3.5 hp Briggs.
Has anyone done this?

I like this garden hose coupling:

http://vintageboatplans.com/trolling/trolling-motor2.pdf

 

[Capt Ron]

Re: The dependable eska

Plastic pipe and hose clamps.... I think that I'll hold back on that.

Here's a question in the mean time. Tightening one clamp on either end of the coupling is easy enough but when the motor is installed how would you tighten the other clamp? Other than drilling an access hole in the side of the exhaust housing this is a closed area. I guess a hole wouldn't be such a big deal since there's no more exhaust involved.

Ok, I think that the plastic hose is a bad idea for a gas motor coupling. The pulsations transmitted through the crankshaft would fail the pipe.

Take a good paddle.

Capt Ron

 

[mckeemm]

Re: The dependable eska

mat_man,

I just sold a 5 hp Sears/Eska that would have been a perfect for a Briggs conversion. It had a water cooled leg with neutral lever and clutch assembly.

I'm putting a 5 hp Clinton J5 back together that uses the same style Eska lower unit but without the water cooling, neutral and clutch assembly. It would be even simpler to do but without neutral it would be a start and go rig.

I also had a chance to get my Briggs doner engine running. I cleaned it up, changed the sheered flywheel key, put fresh gas in it and it started first pull. This little motor started and ran and idled smooth and quiet. I also answered my own question about what to do with the governor controls. It would be very easy to remove the governor arm and linkage and discard it. You can then run your cable throttle directly to the throttle lever. My motor is the Classic 3.5 so it has the plastic carb with fixed idle and high speed settings. Both could be altered but it may not be neccesary.

As far as the hose coupling for the drive goes your biggest problem will be that the Briggs crankshaft is 3/4" plus and the Eska drive shaft is only 1/2". You could weld a short piece of pipe onto the lower unit drive shaft to match its diameter to the crankshaft and use a hose type coupling. I would use a heavy duty hydraulic hose and double clamp with stainless clamps. I think it would be very simple and easy and would last much better than Capt_Don may expect. If you have ever seen the drive coupling in a washing machine it's done much the same and they last for the life of the machine.

If I didn't already have a buyer for the Clinton I would use it. I'm hesitant to make any alterations to the Johnson 5.5 lower I have just in case I decide to rebuild it.

 

[Capt Ron]

Re: The dependable eska

mat_man,

Snip... I would use a heavy duty hydraulic hose and double clamp with stainless clamps. I think it would be very simple and easy and would last much better than Capt_Don may expect. If you have ever seen the drive coupling in a washing machine it's done much the same and they last for the life of the machine.

I would have more faith in the heavy duty hose than the garden hose. The hose clamps would have to be thread locked and evenly spaced to reduce vibration. Ever used an impact wrench on a airhose with a hose clamped fitting? The clamp will constantly loosen from the vibration of the wrench hammering. I have just the right tool for installing the clamps. They would be two turns and then pulled extremely tight, folded over, and then the tabs bent over the end. I think these are Band-It hose clamps. Haven't used it in a while.

The washing machine coupling is under a little different stress because the motor is electric and not producing the power pulses as a 3.5hp single cylinder B&S engine.

Now on this Sears 4hp I think that the lower unit can be assembled while the drive shaft is still inserted in the crankshaft. So, I can attach the driveshaft to the crankshaft and then set the motor in place. Then assemble the lower unit.

One note for future reference: the pinion gear on my 3hp Johnson fits the spline on either end of the driveshaft. If the Eskas, Clintons, or others were the same then an old pinion gear could be a source for the internal spline for these repowers.

All the above assumes that you want to disassemble this repowered motor at some point. However, for a one time deal the old weld the shafts together through a hole in the exhaust housing works rather well and has been used by me on several motors of various sizes when the crankshaft spline strips and the owner takes the cheap route.

Capt Ron

 

[sunkentreasure]

Re: The dependable eska

I've thought about such a project for years....just for the fun of it. In fact there's a junk Elgin hanging in my garage (never throw anything away) that's begging for such a conversion.

On the coupling method...PLEASE don't use the hose/clamps routine. It's cheap sure, but sort of "cheesy" and would probably fail in the middle of the lake. There are better methods, one of which would be a Lovejoy coupling available from McMaster Carr or any industrial supply house. The end pieces can be ordered in different sizes to fit two different shafts, while the center rubber "spider" will align automatically and provide vibration dampening. Costs about 20 bucks or so and is a "proper" method of joining two shafts.

If that doesn't do it for you, run a Google search on "shaft couplings" and you'll find that you're trying to reinvent the wheel. Virtually every conceivable method has been used for many years.