Putting a hole in the transom

[Jorob]

Hi all,

Have been working on my first boat - a Leisure 17. Have been weighing up outboard options, and although 4 or 5hp is generally advised, I have read countless tales online of people needing a bit more oomph when caught in a gale and being blown the wrong way.
Have spoken with a couple of boat mechanics, and they boat (separately) recommended a Tohatsu 6hp Sail Pro. This has 50/50 emphasis on forward and reverse. The trade off - it is an external fuel tank, which means fuel lines.

Does anyone have experience of running fuel lines through the transom? What is best practice/equipment/hardware to use?

For context, I'll mostly be sailing on south/southwest coast of Ireland. I don't plan on using the outboard for everything, but maneuverability when picking young family up from a pier, reliability when those winds blow up out of nowhere etc, I want to make sure I have the right one. Should I ignore the advice and just push ahead with a standard 6hp?

Cheers,
John

 

[Joe]

+

Hi all,

Have been working on my first boat - a Leisure 17. Have been weighing up outboard options, and although 4 or 5hp is generally advised, I have read countless tales online of people needing a bit more oomph when caught in a gale and being blown the wrong way.
Have spoken with a couple of boat mechanics, and they boat (separately) recommended a Tohatsu 6hp Sail Pro. This has 50/50 emphasis on forward and reverse. The trade off - it is an external fuel tank, which means fuel lines.

Does anyone have experience of running fuel lines through the transom? What is best practice/equipment/hardware to use?

For context, I'll mostly be sailing on south/southwest coast of Ireland. I don't plan on using the outboard for everything, but maneuverability when picking young family up from a pier, reliability when those winds blow up out of nowhere etc, I want to make sure I have the right one. Should I ignore the advice and just push ahead with a standard 6hp?

Cheers,
John

You don't need to drill holes for the fuel lines. But even if you decide you need the hole. it's easy to find a grommet that'll fit. You would not put the hole down near the water line anyway, but the grommet will certainly placate your fears. The fuel line is just a rubber, two chambered hose (fuel and air vent) that has easy lock fittings on either end. Super easy to disconnect. Trust me, once you get it installed and running you'll forget all about that issue.
The things you mention are actually reasons you want the SailPro.... it's got the hi thrust prop, which gives you more torque, more desireable because it gives you the extra power without cavitating. Which is what happens when you use a regular pitched prop and take it over the boats max speed limitation. The external fuel tank is a plus. First of all, it'll be larger than the internal version, but the big advantage is making it easier to fill (you can take it to the gas station) especially if you want to add extra fuel while you're out on the water... never know? My SailPro came with a 3 gal portable tank, fuel line with primer bulb and easy changing filter. Finally, the motor is equipped with an alternator that will allow you install a battery to run lights and instruments. Go for it!

 

[Jorob]

Hi Joe,

Thank for the response. The reliability is definitely something that I'm after, and the peace of mind that goes with it.

The rear locker where the tank would be stored is shown below. My worry about just running the fuel line like in the image (from Google) is that the outboard will suffer from fuel starvation if the line is pinched. On my boat there isn't an obvious point for the line to pass through.

 

[BigEasy]

Does anyone have experience of running fuel lines through the transom? What is best practice/equipment/hardware to use?

Easy decision regarding the sail pro; recommendations of two mechanics & excellent advice by an experienced sailor / owner @Joe. Agree with Joe that it isn’t a big concern with drilling thru the upper transom near the gunnel as long as you place a rubber grommet to make it water tight & to prevent chafing the fuel line. If you are hesitant to drill thru the transom, there appears to be a recessed area under the locker (where the red funnel is), where you can drill thru the deck. The fuel line would course under the recessed area, thru the deck, and over the transom . Again, use a rubber grommet in the deck hole.
I also like the idea of a fuel tank. You have extra fuel capacity that translates to fewer refills as compared to an engine mounted tank. When you get low on fuel, simply remove the tank & refill without needing a separate container as necessary to refill the engine mounted tank. A major advantage is if the fuel gets contaminated or if it becomes “stale” during a long off season lay up, its very easy to discard the old fuel & refill without removing the motor. Not sure if the sail pro has an engine mounted filter, if not, install a simple inline filter in the fuel line. And, don’t fret about the hole. You’re a normal sailor; always hate to drill a hole in your boat!

 

[American_Mainsail]

Hi Joe,

Thank for the response. The reliability is definitely something that I'm after, and the peace of mind that goes with it.

The rear locker where the tank would be stored is shown below. My worry about just running the fuel line like in the image (from Google) is that the outboard will suffer from fuel starvation if the line is pinched. On my boat there isn't an obvious point for the line to pass through.
View attachment 226725

Hi @Jorob,

Is that locker vented?

 

[jssailem]

Is that locker vented?

Important question. How of you plan to address the accumulation of gas vapor in the lazerett? I think the saying is “One spark, KABOOM!”

 

[Jorob]

there appears to be a recessed area under the locker (where the red funnel is), where you can drill thru the deck. The fuel line would course under the recessed area, thru the deck, and over the transom . Again, use a rubber grommet in the deck hole.

This image was taken from Google, it isn't my boat unfortunately, and the transom locker varies as they were in production from 1965 to 1990 - an estimated 4500 were produced, so there were tweaks and updates along the way.
I'll get a picture of my own and upload soon for reference, and would be more than happy for you to weigh in. Unnecessary holes are my least favourite kind!
Good shout regarding the inline filter. There is one is the fuel tank pick up, and one in the engine itself, but an inline one might be worth it to be more visible. Particularly with ethanol issues since the increase to 10%.

Is that locker vented?

My own is vented pretty high on the transom. I'll include that when I get pictures.

 

[jssailem]

Welcome Jorob, to the SBO forums.

 

[shemandr]

My first reaction to the OP was how does one get "Caught out in a gale" in a 17' boat? Then I read that you are sailing on the Southern Irish coast. And I looked at the leisure 17 on Sailboatdata.com. It's not the centerboard, trailer launched boat I was picturing. It is a twin keeled (Bilge keel) 17' pocket cruiser displacing around 1,400 lbs. So while I originally thought why would this boat need more than a 3.5 hp 2 cycle engine de jour. Now I see that the the larger SailPro would be a good choice.

 

[higgs]

Can you route the gas line through the vents you say are in your lazarette?

 

[Jorob]

Then I read that you are sailing on the Southern Irish coast.

We go from light breeze to becalmed to force 6 in the space of 30 minutes.

Please ignore the filthy locker - it has been low on my priority list so far!
The vent location is where the red arrow is pointing, so I know that is too far up. The waterline sits a couple of inches below the lowest point on the transom. The locker door/cover sits very snuggly against the rim of the locker, so pinching of the fuel line would definitely occur if I tried to just run it through there without cutting anything out.
The battery box is just temporary while I'm working on the boat, I know I'll need to seal that off separately to prevent possibility of spark.
I don't understand why these boats weren't built with a lower vent to begin with, as the circle cut of visible was originally forholding a propane/butane gas tank, and that was originally routed through to the cab where there was a two burner stove.

 

[jssailem]

Here is one example by a boat owner using a Perko rope deck pipe

A hole in the hull for a fuel line?

Has anyone ever cut a small hole in the hull of the stern to run the fuel line out to the outboard? Right now mine comes out of a fuel tank, and you have to leave the seat open to reach the outboard, which means, you really can't sit on that seat without crimping the fuel line. I was...

forums.sailboatowners.com

The hole pipe and cover look like this.

this one is plastic. They are also made of metal. This approach would allow you to pull the fuel hose in or out of the transom.

If you used quick connectors you could also use a sealed grommet. That would make the hose more of a permanent fixture. Then the connection would be at the motor and the tank.
Something like this in a size to fit your fuel hose.

 

[Project_Mayhem]

I had to lower the motor mount on my transom. I used one old hose for the outboard electrical and the other for fuel. I stuck a brass nipple and a couple of barbs through the transom and used some 4200 to seal it up. Rectorseal was used on the threads as it is safe for gasoline. There's cleaner ways of doing it but they all required more holes. The 4200 lasted only a few years. I'd recommend 4000UV instead

 

[Crazy Dave Condon]

As a former dealer for Tohatsu, I strongly recommend using ethanol free gas to prevent the small jets inside the carburetor from being fouled. Yes there are additives to help prevent this but fouling still occurs which in your case you do not want the motor fail from starting out at the coast when coming in.

 

[Project_Mayhem]

As a former dealer for Tohatsu, I strongly recommend using ethanol free gas to prevent the small jets inside the carburetor from being fouled. Yes there are additives to help prevent this but fouling still occurs which in your case you do not want the motor fail from starting out at the coast when coming in.

Practical Sailor did some testing on these additives. IIRC, they were pretty much useless

 

[Joe]

Hi Joe,

Thank for the response. The reliability is definitely something that I'm after, and the peace of mind that goes with it.

The rear locker where the tank would be stored is shown below. My worry about just running the fuel line like in the image (from Google) is that the outboard will suffer from fuel starvation if the line is pinched. On my boat there isn't an obvious point for the line to pass through.
View attachment 226725

jorob.... this issue has taken way too much of your time. The fuel line that comes with the motor is very robust, thick rubber and unless you kinked it with a set of vice grips ( or some other bizarre occurance) , there is zero possibility of interrupting flow. Another option you have, is to stow the 3 gal tank on the bench in the corner, tie it to a cleat or stanchion, and run the fuel line over the top of the transom to the motor. Like you would if it were a dinghy. No venting issues, the vapor (if any) will drift out the cockpit scupper, and it's a small tank that will pretty much go unnoticed. This style of outboard is designed to be portable. Separating the fuel tank from the motor makes it much easier to handle on and off. It also makes it super easy to rotate the fuel on a regular basis. So.... keep it simple. A chain and padlock is one method, or just lifting off the motor and stowing it below... have fun.

 

[Jorob]

As a former dealer for Tohatsu, I strongly recommend using ethanol free gas to prevent the small jets inside the carburetor from being fouled. Yes there are additives to help prevent this but fouling still occurs which in your case you do not want the motor fail from starting out at the coast when coming in.

Unfortunately, it's part of the European Union climate action plan that unleaded fuel now contains 10% ethanol. The only alternatives that I have found are similar to this fuel, and at €33/$36 for a 5 litre drum, it's not realistic. The recent Tohatsu models are apparently built to tolerate it, but I will be winterizing the outboard along with the mechanic, and I'll probably run the last litre of the season through as the expensive fuel.

... run the fuel line over the top of the transom to the motor.

this is what I'm going to go with for what is left in the season, and I'll make a decision once it comes off the water if I want to make holes in my boat over the winter. If I do want to go that route, something similar to what @jssailem has mentioned above seems like it could be a good option for fuel line running.
One of the mechanics I spoke to seems to think that the existing vent is enough, despite it being up so high. I remain unconvinced...

Thanks to all for the input!

 

[ShawnL]

I have a '72 Catalina 22 (so what do I know) but when we are sailing, we throw the fuel tank on the cockpit floor near the transom, attach the fuel line and go. When we're done motoring for an extended period of time (ie not just day sailing) the tank gets detached and goes back into the locker. Otherwise, we just put up with it in the cockpit. It's 5 gallons (US) so it doesn't take up that much room when we're expecting to use it.

 

[Jorob]

we throw the fuel tank on the cockpit floor near the transom, attach the fuel line and go. When we're done motoring for an extended period of time (ie not just day sailing) the tank gets detached and goes back into the locker.

Thanks @ShawnL, got the boat in the water this weekend and this is what we did. With a 2 year old and a very curious 5 year old, we'll be sure to stow the tank at every opportunity. Anyway, we're here for the sailing, not the motoring.

I went with the Sail Pro in the end and it is a great outboard from what I can see so far. Obviously as it's new, need to run it at about 50% for the first couple of hours, but even at 1/4 throttle it was pushing along nicely. Wind picked up and the tide current turned, and it became obvious that having that extra bit of power was the right decision.

Mechanic said that it's rated for the E10 fuel, and while I believe him, I still bought the Starbrite Star Tron for petrol engines. I picked it up at the chandlery and the owner made a beeline for me to tell me how fantastic it was over everything else (and no, it wasn't the most expensive there). In my area, a lot of the engine issues are coming from the ethanol also breaking down the lining of the fuel lines, so anything that can possibly help, I'll do. Did a test of fuel in clear bottles - one with additive, one without. The one without additive had clear separation after just a couple of days, with the ethanol sinking to the bottom.

 

[American_Mainsail]

Thanks for the info on the Star Tron.

I've been using StaBil Marine 360 religously in all of my small engines (including my dinghy outboard). It seems to cut down on arb issues by reducing corrosion in the carb, but I still need to clean the carburetor once a year due to gumming issues. My next step is to install a fuel/water separator.

Last weekend, my outboard stopped revving above half throttle. It was time for carb maintenance. When I drained the carb, there was a water/ethanol solution sitting in the bottom of the float bowl. I'm looking forward to seeing whether a fuel/water separator will greatly minimize the buildup of water and ethanol in the float bowl. My theory is that the water and ethanol in the float bowl is the source of the gumming and corrosion.