Outboard on a Catalina 27

[new-to-sailing]

Appreciate the replies! Great to see an example of someone powering a similar sized boat.

I am going to go with the long shaft (20") as in the short term powering the sailboat is more of a priority. I shouldn't have any issues mounting it fairly close to the water getting a lot of the shaft submerged so don't see a ton of upside for the 25" especially if I consider future dinghy use. I will also get one of the sailpro models.

I am still torn between the Propane and gas, if I am not worried about availability of the propane are there any other downsides? I like the idea of using propane for storage, fuel quality, and simplicity. I've also read that the carburetor on a gas engine can have issues if not run frequently (I have no experience with gas engines) so keeping the system simple and lower maintenance certainly a plus for me.

[NorthCoastJoe]

I had in the past a Leer 5 hp propane that held a #1 camp stove bottle of propane on the engine. So no need for a big bottle.

If you go with gas when you shut down disconnect / shut off the fuel and run it until it uses all the fuel in the carb and you will have no problems. Do that with all small motors.

I have been doing that with a chainsaw that is now 35 years old and I have never had a problem, never touched the carb in 35 years.

You might get a good motor on Craigslist. I have gotten a few that way.

[Adelie]

Originally Posted by new-to-sailing

Appreciate the replies! Great to see an example of someone powering a similar sized boat.

I am going to go with the long shaft (20") as in the short term powering the sailboat is more of a priority. I shouldn't have any issues mounting it fairly close to the water getting a lot of the shaft submerged so don't see a ton of upside for the 25" especially if I consider future dinghy use. I will also get one of the sailpro models.

I am still torn between the Propane and gas, if I am not worried about availability of the propane are there any other downsides? I like the idea of using propane for storage, fuel quality, and simplicity. I've also read that the carburetor on a gas engine can have issues if not run frequently (I have no experience with gas engines) so keeping the system simple and lower maintenance certainly a plus for me.

Fuel issues for motors not run for long periods are in large part but not completely related to the ethanol in the fuel. Ethanol absorbs water which clogs the jets with gummy deposits.

The 2 solutions are to not get fuel with ethanol in it or remove it from the fuel you buy.

My brother in law in MN has one service station he knows of in his small city that has non-ethanol fuel at a slight cost premium. There is no ethanol free fuel in California that I have been able to find.

To remove ethanol....... add water.... and dark food coloring. Ethanol is hydrophilic and would rather mix with water than gasoline. Add about 1/2gal water to 5gal fuel in a clear jug with a tap at the bottom. Shake it up and wait 15min. The water ethanol mixture will be colored making it easier to discern water from fuel when discharging the mixture. You should get about 1gal of water/ethanol mixture leaving you with about 4.5gal gasoline.

Ethanol is an octane booster, about 2pt or so. So either start with a premium fuel or use an octane booster after removing the ethanol. Some octane boosters are ethanol so be careful about which one you buy.

[new-to-sailing]

Originally Posted by Adelie

Fuel issues for motors not run for long periods are in large part but not completely related to the ethanol in the fuel. Ethanol absorbs water which clogs the jets with gummy deposits.

The 2 solutions are to not get fuel with ethanol in it or remove it from the fuel you buy.

My brother in law in MN has one service station he knows of in his small city that has non-ethanol fuel at a slight cost premium. There is no ethanol free fuel in California that I have been able to find.

To remove ethanol....... add water.... and dark food coloring. Ethanol is hydrophilic and would rather mix with water than gasoline. Add about 1/2gal water to 5gal fuel in a clear jug with a tap at the bottom. Shake it up and wait 15min. The water ethanol mixture will be colored making it easier to discern water from fuel when discharging the mixture. You should get about 1gal of water/ethanol mixture leaving you with about 4.5gal gasoline.

Ethanol is an octane booster, about 2pt or so. So either start with a premium fuel or use an octane booster after removing the ethanol. Some octane boosters are ethanol so be careful about which one you buy.

When removing the ethanol after mixing it up are you then just able to hand pump out the ethanol, assuming it's pretty easy to see and groups together?

[thomm225]

Originally Posted by new-to-sailing

When removing the ethanol after mixing it up are you then just able to hand pump out the ethanol, assuming it's pretty easy to see and groups together?

You don't need to worry about the ethanol. The new engines are built for it.

Just use Sta-Bil in your gas if you don't plan to use it all in a month or two.

[Adelie]

Originally Posted by thomm225

You don't need to worry about the ethanol. The new engines are built for it.

Just use Sta-Bil in your gas if you don't plan to use it all in a month or two.

Partly true. When they first started adding ethanol to fuel there were a lot of problems with rubber gaskets and membranes breaking down because they weren't formulated to resist action by the ethanol. Car, outboard and other engine manufacturers responded by choosing different materials that would resist ethanol attack. Still a problem with older car engines and outboards. This is the true part.

The not true part is that there is still a problem with ethanol. Ethanol is a solvent for varnishes and deposits left behind on tank and fuel line walls. The ethanol breaks them free so they can travel with the fuel to the carb and block the jets. This is more of a problem with small engines that have smaller jets. Generally this isn't a big problem if the engine is being used often and the fuel in the tank is cycled regularly. Consequently there is only a 10% solution of ethanol coming into contact with these deposits.

However ethanol is hydrophilic which means it likes to mix with water, it will happily absorb water that condenses in the tank. For small amounts of condensation in the tank the ethanol is beneficial because the ethanol can hold the water in suspension so any water going to the carb is in small disbursed amounts that vaporize without significantly affecting combustion. But, when the water content gets high enough, the ethanol and water will separate out of the fuel and sink to the bottom because the water-ethanol mixture is denser than the fuel. This does several things, it means there is a much higher percentage of ethanol in contact with the varnished tank and plumbing so the ethanol breaks those deposits loose a lot faster, and the bottom of the tank is where the fuel pickup is so if there is enough accumulation of the mixture, that is what is delivered to the cylinders and the it doesn't burn like fuel so the engine won't start even if the jets aren't clogged by the loosened deposits.

Also, ethanol is an oxidizer, part of why it in the fuel to begin with. It helps the fuel burn more completely reducing smog. But as an oxidizer it will attack metal parts releasing rust and other oxides into the fuel stream to clog jets. When the fuel builds up water enough for phase separation to occur, the concentrated mixture of ethanol and water attacks metals even faster.

What do stabilizers do? Various things, increase the amount of water that can be held in suspension, decrease the freezing temperature of the water that is absorbed, slows evaporation of the fuel and they are anti-oxidants.
-A small number of the stabilizers will increase the amount of water that can be held in suspension by about 8%, so a gallon of gas can hold 3-1/4tsp of water in suspension instead of just 3tsp, most stabilizers don't do this.
-Anti-oxidation is the big thing. Gasoline is a mixture of various hydrocarbon compounds. As oxygen is absorbed into the fuel some of them, the aromatics, oxidize and break down and the fuel goes sour. The stabilizer acts as a sacrificial compound that oxidizes first before the desirable aromatics oxidize.
-Certain stabilizers will also inhibit the corrosion of metal in contact with the fuel/ethanol-water mixture.

On the whole stabilizers have little if any effect on the negative effects of ethanol fuels stored for significant periods.

https://www.originalair.com/the-best...d-bad-and-ugly
https://cropwatch.unl.edu/documents/...2009052014.pdf
https://cropwatch.unl.edu/ethanol-an...oval-additives
https://www.boatus.com/expert-advice...yths-clarified

[thomm225]

Originally Posted by new-to-sailing

Appreciate the replies! Great to see an example of someone powering a similar sized boat.

I am going to go with the long shaft (20") as in the short term powering the sailboat is more of a priority. I shouldn't have any issues mounting it fairly close to the water getting a lot of the shaft submerged so don't see a ton of upside for the 25" especially if I consider future dinghy use. I will also get one of the sailpro models.

I am still torn between the Propane and gas, if I am not worried about availability of the propane are there any other downsides? I like the idea of using propane for storage, fuel quality, and simplicity. I've also read that the carburetor on a gas engine can have issues if not run frequently (I have no experience with gas engines) so keeping the system simple and lower maintenance certainly a plus for me.

So I had to get around some tankers here and if I didn't have a 25" shaft outboard, it would have been coming out of the water.

Once around I went back to motorsailing. (as in sail assisting the motor)

I still had 20 miles to go and wanted to get back before like 2-3 pm

Notice the main is reefed.

With the outboard just above idle, you can point a lot closer to the wind.

https://www.youtube.com/watch?v=ri0c5GnZ1I8

[sanibel sailor]

Get what works for the C27. Temporary arrangements tend to become permanent when the other solution is expensive.

[MartinF]

Why is this temporary? If it is because you have a non-working inboard engine the best solution is to fix the engine now. If you put a short-shaft engine sufficiently low on your stern you will have problems accessing the engine controls, and the engine is likely to get wet when you are heeled in a chop. The dinghy is another question. If you aim to carry the dinghy you will only have space for the smallest possible soft dinghy. Planing is irrelevant. Lifting a 60lb engine over the rail will be impractical/impossible. Get a 2 or 3hp motor or a 6' pair of oars. Towing a dinghy is an alternative. You could tow a solid boat which would be easier to row/paddle.
Good Luck,
M

[Cheechako]

Originally Posted by sanibel sailor

Get what works for the C27. Temporary arrangements tend to become permanent when the other solution is expensive.

This is a good thought. How sure are you you will install a new diesel?

Also, with a 5 hp dingy OB, you are not doing much planing anyway. With a lightweight airfloor dingy and one person you can plane. With a RIB or etc probably not. You can put-put along fine with a long shaft on the dingy if you are not planing much anyway.

[new-to-sailing]

Originally Posted by Cheechako

This is a good thought. How sure are you you will install a new diesel?

Also, with a 5 hp dingy OB, you are not doing much planing anyway. With a lightweight airfloor dingy and one person you can plane. With a RIB or etc probably not. You can put-put along fine with a long shaft on the dingy if you are not planing much anyway.

Yup, been thinking about this more and more and it’s a very good point. I’m fairly confident my current diesel will get up and running within the next month but who knows when the next issue will pop up.

To thomm225’s point yup it’s older a 1989 Universal M3-20, although it doesn’t have a ton of hours on it I’m just not sure of it’s maintenance history. The current problem I have is with the injection pump which I’ve been told really shouldn’t fail which causes me concern about the overall upkeep and quality of fuel that was used with it. I am planning to remove it this winter to clean the area and the engine and fully service it which could very easily turn into a longer term project.

[Cheechako]

Originally Posted by new-to-sailing

Yup, been thinking about this more and more and it’s a very good point. I’m fairly confident my current diesel will get up and running within the next month but who knows when the next issue will pop up.

To thomm225’s point yup it’s older a 1989 Universal M3-20, although it doesn’t have a ton of hours on it I’m just not sure of it’s maintenance history. The current problem I have is with the injection pump which I’ve been told really shouldn’t fail which causes me concern about the overall upkeep and quality of fuel that was used with it. I am planning to remove it this winter to clean the area and the engine and fully service it which could very easily turn into a longer term project.

Hmmm, well if your diesel is potentially running in a month, that's different. I thought it was defunct. Then I'd go with a good bracket and a short shaft maybe...

[new-to-sailing]

Originally Posted by Cheechako

Hmmm, well if your diesel is potentially running in a month, that's different. I thought it was defunct. Then I'd go with a good bracket and a short shaft maybe...

This decision will be the death of me lol

[OneBoatman]

I agree with many of the posters don't go for the propane fueled outboard, I've met very few folks that were please with that choice. Is 5 H.P. big enough, technically yes but I would say not if you will bucking significant current frequently. You will need a bracket that allows you to drop the lower unit to the proper working immersion depth and a short shaft that is better suited for a dinghy will likely over-rev when you are in steep stuff, but hopefully that will not be too often. If the transom of your Catalina is nearly vertical and there is space to port or starboard to mount a spring-assisted drop type bracket that allows you to reach it from either the cockpit or transom gate area you should be ok. Be sure to thru-bolt and back the bracket so that it is strong enough to support a slightly bigger motor such as an 8 or 9.9 H.P. long shaft motor should you choose to stay with outboard power and then use the 5 H.P. motor for your dinghy.

[SV_FlyingTigress]

See the watermark on the long shaft Tohatsu 9.9 in the picture of my catalina 27 for required shaft size