Propane Outboards

[CCBullseye]

From all I have seen and read, it seems like a propane powered outboard is a great idea inside the US. Outside the US, there seems to be some serious problems with obtaining fuel, so maybe it might not be the best idea for a world cruise.

[S/V Antares]

The reason to own a small propane engine for the dink is not how great propane is but how crappy the US gas is. 10 -15 % ethenol is murder on small engines. Startron or other additives help but not enough. E15 gas will hardly burn with a match after a few months.

It is easy to get propane in the Bahamas and Caribbean as it is much more widely used for cooking. LPG is a mix of Butane and Propane.

If you are a dock dolly and only use the dink once in a while it is ideal

[WGDM]

I think its a great idea----carb trouble from poor fuel in less developed areas is a a pain and very commo---- and less or no smoke.Lots of taxi`s in places like St Thomas run on either propane or CNG (not sure which) and in a dinghy I cannot see any safety concerns from using propane.Fill the can as you would for your stove.Suzuki has a great outboard which runs on kerosene;The fuel tank is divided into small and large partitions for gasolene (easy starting when cold) and kerosene for easy cheap long-distance running when hot in areas where gasoline is difficult to find.The kerosene also provides the lubrication that a 2-stroke needs.Four-strokes are not really the answer for small dinghies----too heavy and bulky,in my opinion-----and too complicated with the overhead cams and valves etc.

[capngeo]

Originally Posted by Irish rambler

Quite simply the same reason petrol inboards in this part of the world are as rare as rocking horse manure, fire hazard ! and yes there have been 2 boats to my knowledge blown up. Availabilty and storage are 2 other major issues. I agree it's great for forklifts, stationary engines etc etc and I totally agree the engine runs very clean but on a boat, no way. Ordinary propane/butane for cooking is the only gas on board,and that religiously stored and monitored. I'm afraid I'll have to agree to disagree on that one. sorry.

My boat is 30 years old and has had propane on board for every second of those 30 years... no explosions!

[WGDM]

We are talking here about little dinghies,not cruising boats.I am sure that we are all aware that gasoline cruising engines installations are now out of fashion---diesel being the fuel of choice----but there is absolutely no reason propane cannot be used to power 8' dinghies with 5 hp engines.Lets move forward to 2012 and beyond and try to go green and clean and advanced...
G

[HopCar]

While propane should be stored and used as you would gasoline I believe it is actually a little safer.

It will ignite in only a very narrow range of mixtures with air. Below about 2% is too lean for the propane to ignite and above about 10% the mixture is too rich. Gasoline will ignite in a broader range of mixtures.

It takes a temperature of about 900 def. F to ingnite propane but only about 500 deg. F to ignite gasoline.

I'm not sure but I believe propane gas is lighter than gasoline vapors and will disperse more quickly.

These aren't big differences but I think they give the edge to propane safety wise.

[roberttigar]

Per the mfr, the 2.5hp leghr will run for approx 3/4 hr on a 1lb propane tank and approx 1/2hr at full throddle. Bob

[osirissail]

I have a 5hp outboard for my little - 8.5 ft dinghy and almost always run it at full throttle backed off a little bit because somebody told me that was better.

So the 1/2 hour on 1 lb. - a 5 lb tank would be 10 hours which seems reasonable.

But I would suggest getting or making the adaptor hose and fittings to refill the little tank from a bigger tank onboard that you use for the oven/stove. Also learn about how to do the transfer as you need to be able to open the manual bleed screw on the tank you are filling to allow a pressure differential between the two tanks to move the propane from one to the other.

[Celestialsailor]

I'm wondering if there will be a retro-fit for current gasoline outboards (4 strokes of course). I know they can do this with forklifts. I'd rather carry 3 aluminum tanks of propane onboard, rather than 2 aluminum tanks of propane and on thin plastic tank of gas. If the conversion was $200, I'd do it.

[HopCar]

Roberttigar, I think those are the numbers for the 5 hp engine.

Celestialsailor, Gasoline outboards have been converted to propane for use in areas sensitive to polution. The drawback is that you lose a little power. A 5 hp gasoline engine converted to run on propane might only put out 4.5 hp. I wouldn't be surprised if there were kits to do the conversion now. I had my lawn mower shop convert a couple of generators from gasoline to propane. They lost a little power but at least they always start when I need them.

The Lehr engines are designed to put out their rated hp and take advantage of the 110 octane of propane by running at a higher compression ratio.

[Kettlewell]

I like the idea of a propane outboard. If for no other reason than the clean burning, and the lack of problems with ethanol and gasoline degrading in storage. Does anyone know if the figerglass/composite tanks are refillable and legal everywhere, at least within the USA? How much do those things cost? I see this information on the Lite Cylinder website, but has everyone found that propane filling stations accept them?

[HopCar]

We had one filled for use in our booth at the Ft. Lauderdale boat show. We didn't have a problem but that was just one example. You really shouldn't have a problem. They come with the correct valve and have the DOT certification. Outside the US? No idea.

Aluminum tanks are also an option. I'm looking at the 10 pound horizontal aluminum tank. Mounted on a piece of starboard, it should be very stable in the bottom of a small boat.

[Kettlewell]

One problem I see with either the aluminum or fiberglass tank in a dink is you are leaving something there worth more than $100 that would be easy to steal--though I suppose you could chain it to the motor. Pretty hefty when filled too. Also, there are very few places right on the water that fill propane, even in the USA, and they aren't supposed to be carried on buses. Most taxis will take them I have found. Hmmm--I'll have to start noting down propane locations near the water.

[osirissail]

You had better Chain and lock both your motor and fuel tank - whether propane or gasoline or either or both will disappear quickly if you are in the Caribbean. This is just the way things are now-a-days especially with high gasoline prices

[DWJ]

Has anyone heard the 2.5 run? Watching the videos, it seemed to be a loud little motor.

Just as an FYI I emailed questions to the Lehr customer service dept twice and both times I received responses within an hour.