Propane Outboards

Ever thought about a propane outboard? Clean, simple, reliable. Here's a 2.5 hp @ $1k,and a 5 hp @ $1.5k. www.golehr.com.

Like the idea for a few reasons:

1 less fuel on the trawler if you are already carry propane.
Fuel doesn't go bad over time.
4 cycle propane motors are much cleaner internally with less carbon build up.

Definition of a pessimist is an optimist with experience. Last 2 early adopter options I bought into didn't work out well. I'll be waiting on the side lines rooting for them for a couple of years.

Ted

Since they are converted 4 stroke engines they are just as heavy (almost) and the little ones probably shake just like the 4 stroke gasoline engines.

I wonder why they did'nt make 2 stroke OBs w propane. They do'nt need chokes so starting should be easy and they are clean burning. Hmmmmmm
I'm sure there is some reason though.

manyboats said:

I wonder why they did'nt make 2 stroke OBs w propane. They do'nt need chokes so starting should be easy and they are clean burning. Hmmmmmm
I'm sure there is some reason though.

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Betcha it's about lubrication.

Ted, they are having some teething problems but I think that will be resolved very soon. I played with one at the Miami International Boat Show. It runs so clean that they were allowed to run it inside the convention center. There are plans for a ten hp motor to follow the 2.5 and 5.

Would love to buy one just don't like beta testing anything except apps and computer programs. Propane is an ideal fuel for small industrial engines, it should work equally well for small outboards IMO.

Mark wrote:
"Betcha it's about lubrication."

The engine would need to be oil injected........like my 40 e-tech.

"I wonder why they did'nt make 2 stroke OBs w propane".

"The engine would need to be oil injected........like my 40 e-tech"

No problem , Styer Damler Puch refined the oil pumping system after WWII.

Just takes an oil tank, might be a great place to lube with dead french fry oil.

A GREEN!! 2 stroke! That smells good!

FF

manyboats said:

Mark wrote:
"Betcha it's about lubrication."

The engine would need to be oil injected........like my 40 e-tech.

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But that would effect the clean burn and defeat the clean burn purpose.

JD,
You mean that's the whole point of it ..... to be green?

I had a propane Buick once. Ran perfect all the time except when I'd switch back to gas. Only did that to keep the gaskets in the carburetor from going south. I told my dad he should convert his Cadillac to propane and he about had a fit that I would suggest such a repulsive thing. The thought of someone in his Cadillac getting a possible whiff of the smell of propane .....ewew

JD, seems to me the Evinrude people claim the e-tech series has less emissions than a 4 stroke. And the small amount of oil the engine goes through is almost scary.

manyboats said:

JD,
You mean that's the whole point of it ..... to be green?

JD, seems to me the Evinrude people claim the e-tech series has less emissions than a 4 stroke. And the small amount of oil the engine goes through is almost scary.

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If that is true and I'm in favor of it being so, then why do they not make a smaller 2-stroke that meets the EPA requirements? They would sell a million of them.

Evinrude makes a 15hp E-Tec motor, but it weighs 177lbs! The injectors are electrically operated, and use a lot of 12 volt power, so the engine needs a large alternator. The 15hp is the same weight as a 25hp E-Tec, probably is just a detuned 25.

As far as the oil needed to lube the engine.....I used to work at the Torrington Company and they made the main and rod bearings for the OMC 2 strokes and Merc 2 strokes. We also tested them in our lab.
The bogey was x number of hours ( I recall it being 250 but I could be wrong) at 2500 rpm in a test tanks (with a load wheel) with no oil at all in the mix.
It is surprising how little oil they really need to survive light duty.

I like these engines but 177lbs for 15hp is sick!

Anybody know if these e-tech's are cleaner than the 4 strokes? I think it's true but only under certain conditions like at idle or at high load or whatever.

CNG Outboard

We just a tour on the San Antonio Riverwalk by boat and got a pic of the old outboard. All run on CNG.

BTW, the outboard is not indicative of the area. A shameless plug for the area. Our first time here and it is awesome, laid back. Beautiful native montezua cypress trees provide shade as you explore the endless restaurants, shops and locations to get a frozen margarita "with salt please"!

The there may be advantages to a propane fuelled outboard, but the main disadvantage I see is the difficulty of obtaining fuel, especially if you manage to run out while on the water. You can buy, borrow, or steal gasoline fairly easily, but I doubt you can call TowBoatUS or SeaTow and ask them to bring you a few gallons of propane.

If they ever become mainstream, that may change. I'll wait and see.

manyboats said:

I like these engines but 177lbs for 15hp is sick!

Anybody know if these e-tech's are cleaner than the 4 strokes? I think it's true but only under certain conditions like at idle or at high load or whatever.

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Eric--- In investigating the notion of repowering our 17' Arima the other week at Jacobsen Marine in Seattle here is what I learned:

We currently have a 90hp 2-stroke Yamaha on the boat, original to the boat. Yamaha does not make a 90 hp 4-stroke, so the choices for our boat are 100 hp or 70 hp. (Yamaha no longer sells 2-stroke engines of any kind in the US).

Jacobsen also sells Evinrude 2-stroke E-Tech engines. Advantages I was told for the Yamaha are cleaner and quieter. The advantage cited for the E-Tech is lighter. The Yamaha 100 hp is way heavier, the Jacobsen guy said, than the equivelent power E-tech.

While weight is certainly a consideration we would get a 4-stroke for the boat, either a Yamaha or a Honda. We would not get the E-Tech.

Marin said:

............. We would not get the E-Tech.

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You obviously have some unspecified predudice against the E-Tech, but what about the additional weight of a modern four stroke outboard on your boat? Many people have reported problems when repowering a small boat with a heavier engine.

If your boat was designed for a 300 lb outboard, you should really stay pretty close to that to avoid problems.

Another consideration, and this is from memory, haven't googled it. As I remember from a class. LP is 100 octane that sounds great. But it produces less BTU's than gasoline not great. Less power. Never really noticeable on a forift but on a high reving outboard??

rwidman said:

You obviously have some unspecified predudice against the E-Tech, but what about the additional weight of a modern four stroke outboard on your boat? Many people have reported problems when repowering a small boat with a heavier engine.

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I don't have a predjudice against the E-tech technology, I have a predjudice against Evinrude motors (and Johnson and Mercury). If Yamaha or Honda were using this technology and it had a proven track record we'd probably consider it if the weight advantage made a significant difference.

The 17' Arima Sea Ranger is rated for more than 100 hp. I've seen them with 115 and 120 hp motors (2-stroke) although the most common power over the years has been 70 and 90. So I think our boat would do fine with the 100 hp 4-stroke Yamaha in terms of weight. I've seen a fair number of them so it seems to be a popular engine for that boat.

We have not yet looked into what Honda has on offer in our power range.

Forkliftt said:

But it produces less BTU's than gasoline not great. Less power. Never really noticeable on a forift but on a high reving outboard??

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Propane contains about 30 percent less energy per unit of volume than gasoline. That doesn't mean you can't get the same power from burning it, you just need to burn more to get it.

you must remember that there are a lot more moving parts in a 4 stroke then there are in a 2 stroke that can go wrong???????

That's true. That's why it pays to buy a reputable brand of four-stroke which is why there are only two brands of outboard we would ever consider buying. More moving parts does not inherently mean more operational failures and less reliability. It might mean more frequent service intervals or a lower tolerance of lousy maintanance and abusive operation, however.

A 4-stroke engine made by a mediocre manufacturer may have reduced reliability compared to a 2-stroke made by the same mediocre manufacturer for the reason you state. But I believe that if you buy a 4 stroke made by a top-notch manufacturer there's no reason it can't be as reliable as a 2- stroke made by the same top notch manufacturer.

Marin said:

...which is why there are only two brands of outboard we would ever consider buying...

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And they are?

Yamaha and Honda.

Forklift, you're right about the lower BTU's and the higher octane (110 I think, one of us should look it up!) but an engine designed to put out 5 hp on propane has just as much power as an engine designed to put out 5 hp on gasoline. You only lose power if you convert an engine designed to run on gasoline to propane. You could also make up a lot of that loss by installing higher compression pistons to take advantage of propanes higher octane rating.

I guess our assistance towing boats will start carrying the small propane tanks used for camp stoves/grills just like we carry gas/diesel and spare oil.
Will be no big deal if that's what out customers need/want.

Marin said:

I don't have a predjudice against the E-tech technology, I have a predjudice against Evinrude motors (and Johnson and Mercury). If Yamaha or Honda were using this technology and it had a proven track record we'd probably consider it if the weight advantage made a significant difference.

The 17' Arima Sea Ranger is rated for more than 100 hp. I've seen them with 115 and 120 hp motors (2-stroke) although the most common power over the years has been 70 and 90. So I think our boat would do fine with the 100 hp 4-stroke Yamaha in terms of weight. I've seen a fair number of them so it seems to be a popular engine for that boat.

We have not yet looked into what Honda has on offer in our power range.

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I've read several posts on the forums that cater to smaller boats where owners have replaced two stroke engines with heavier four stroke engines and are now asking how to correct weight distributin problems as a result of the replacement.

What you might want to do is add temporary weight to the stern to simulate the additional weight of the replacement engine before investing several thousand dollars.

Or not, your choice.

Marin we have an 18' OB w a 60hp and it does fine as long as it's not over loaded and one shouldn't do that anyway.
If you were to be time traveled to 1965 or so you'd be say'in the same thing except that the only OBs you would buy would be OMCs or Mercurys.
Generally speaking propane engines (not motors) will produce about 5% less power than gasoline in cars that aren't emission controlled but w some or many emission controlled car engines 5 to 10% more power may be had.
Many house boat rentals have been propane powered for at least 30 years. With the old FP Bearcat 4 stroke.
With oil injection I don't see why any old (or new) two stroke couldn't be converted to propane.

I've read several posts on the forums that cater to smaller boats where owners have replaced two stroke engines with heavier four stroke engines and are now asking how to correct weight distribution problems as a result of the replacement.

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Our current engine only has about 300 hours on it. The problems it's had have had more to do with long periods of disuse than actual motor problems. In fact the only actual motor problem we've ever had was the partial failure of the stator last year. So for now we will continue to use the 90 hp Yamaha 2-stroke.

However this engine is now 25 years old and it's pretty inefficient to say nothing of polluting, so I foresee the need (or desire) to change it at some point down the road here a bit. It will depend on how much we continue to use the boat. But while the Yamaha 100 hp 4-stroke is, IIRC, about 100 pounds heavier than the equivalent Evinrude E-Tech 2-stroke, the additional weight does not seem to be an issue for the model of Arima we have.

I haven't looked into what Honda has in the 80-100 hp range so there may be an option there, too. But regardless there is no way we'd ever put an Evinrude motor on the boat anyway so the E-Tech issue is sort of moot.

And we have no interest whatsoever in converting our current engine to propane. Be like converting a Model-T to propane--- it might run okay on propane but it'd still be a Model T.