propane vs gas 5-6HP outboards?

[MikeHoncho]

Originally Posted by JBP

If you have propane on your boat, you can refill them yourself. Note most 1 pound camp stove tanks are not refillable, you have to look for the refillable kind (though some people have figured out how to refill the non-refillable tanks).

Refilling tanks via the transfer method isn't advisable unless you know exactly what you are doing. Overfilling them will not give enough vapor space for liquid expansion when it warms and the vapor pressure of the liquid increases.
Both causing increased pressures within the cylinder. This will cause the relief valve to open (hopefully) and release liquid propane that expands 270:1! Not good. Worst-case scenario is that the tank ruptures.

I'm very familiar with LPG, and I immediately use a tank after I refill it to generate vapor space. I do this even after weighting post-fill.

[Tortuga's Lie]

Gasoline really isn't an issue IF you get into the habit of running the gas out of the carb when you know you won't be using it for more than a few days by closing off the valve or unplugging the fuel line. Make sure you use non-ethanol gas and use a fuel stabilizer. Non of these steps are particularly onerous, just have to abide by them or your injectors/carb will suffer.
As far as storing gasoline onboard, I use a 5 gallon portable fuel tank for my outboard and do not need to store gas on the mothership. I have a Honda 5hp that can use either a portable tank or the built in tank. My 9.9 Johnson uses a portable as well.

[Ryban]

Originally Posted by Nicholson58

Refilling in the Caribbean and almost anywhere outside of the US is way more expensive for propane, takes several days with a courier. French islands have no propane. LNG does not exist. Electric is incapable of long transits. It is slow especially with people and groceries. Distances are often two miles or more and sea/wind state frequently difficult. Charging will often require your generator. Three electric OBs failed utterly due to water ingress last season on the Salty Dawg rally. Many high density (non-LiFePO) are responsible for boat fires although the OBs have not been implicated.

Gasoline is ubiquitous. We run 15 HP. This is about the average. It can plane your boat, get you to a dive site with tanks, rescue your boat.

While this is good and valid info, it seems like the poster is primarily looking to putz around in the harbor, which I think is actually a perfect use-case for an electric outboard, and a lot simpler/safer than propane or gas.

If you have an adequate amount of solar, and you're not taking 5 mile trips in the dinghy every day, you certainly don't need a generator to charge your battery.

[Pete7]

Originally Posted by Nicholson58

Yes, however, that is butane and may require orifice modification of the appliance and adapters to connect to your system. Your propane tanks will not be filled there. Only swap tanks are available so you must buy tank #1. Tanks are steel, blue paint and almost always rusty. The connection port is usually beat up and scary. Do you want two sets of tanks, propane and gaz, on board? Is your locker big enough? What do you do with the gaz tanks when you leave?.

Thanks, interesting and similar to the European system of exchanging cylinders rather than owning. Most stoves now can accept butane or propane, assuming the regulator is changed first which controls the difference in pressures.

Camping Gaz very popular in Europe and cheap as chips (16 Euro) even if the 907 cylinders are only 2.7kgs or the 904, 1.8kgs. Sadly the UK price for Camping Gaz is £45 for a 2.7kg exchanged or £60 if you don't have one to exchange. We solved the problem by going electric cooking but did keep one 1.8kg cylinder and a single gas hob just in case.

Pete

[FlyingScot]

Originally Posted by MikeHoncho

Most major brands offer propane versions.

They must not be hot sellers as I never see propane outboards where I boat.

Anyone know of the reliability of these brands? I've heard so many LEHR complaints I would never consider them.

I see Mercury makes 5HP at 60 lbs and runs about 5 hours on 1 standard USA sized tank.
This must be a Tohatsu rebadge.

[sailingharry]

Originally Posted by FlyingScot

I see Mercury makes 5HP at 60 lbs and runs about 5 hours on 1 standard USA sized tank.

Propane suffers from many of the same limitations as electric, and so fits many of the same appropriate use cases.

They (both) are ideal for uses where expected use is low power, low daily run time, and infrequent use. Outstanding for weekend cruisers who mostly use the outboard on weekends to go short distances.

When we are actively cruising (not this year, but the two prior years), we typically run our 9.8hp WOT for two dog runs a day (sometimes more) for upwards of 3-4 hours a week. Seeing that a 5hp is good for 5 hours on a 20 lb tank, we would be needing a tank fill every 1-2 weeks. Yikes! That is in line with our experience , where a 3-gal tank takes 1-2 weeks to empty (I believe a 20lb propane tank has about the same heat value). Similarly, an electric motor would be vastly slower, and require much more engine run time to make the electricity.

[boating4ever]

some cruising destinations dont sell propane, or its very difficul to get