Fuel leaks after use or refilling

[Idiotfool]

Hello, friends.

In my old 2008, my fuel tanks have the quick connect barbed fittings in the fuel lines for Evinrudes. When I top off or disturb the tanks in any meaningful way, the firings will start to slowly leak fuel.

What can be done?

I disconnect both when I return home, but even if I left one connected, the other would still be an issue. I tried looking for caps for the plugs, but that's a hard find. Going someone just has a solution for me.

Thanks in advance!

[kenfyoozed]

Are they leaking due to pressure build up?

[Russ]

Where exactly are they leaking?
Where the hose meets the fittings (clamp). Or where the fitting attaches to the tank/motor?

How old are your lines?

I had to double clamp my hoses to the external fuel filter because it was leaking. Although later the hose cracked which may have been the root of the problem. First time I installed this new fuel line it cracked lengthwise. Junk hose. Might be the reason I had to double-clamp them.

[Piddle and Futz]

Ended up replacing our original tanks just for that reason... so weather worn that the gasoline seemed to seep out through the plastic itself.

We're much happier (and probably a lot safer) with that small investment.

[NiceAft]

Piddle and Futz wrote:

(and probably a lot safer)

Reminds me of an old ditty sung to the tune of My Bonnie Lies Over The Ocean

My Bonnie looked into a gas tank
The contents she wanted to see
She lit a match to assist her
Oh bring back my Bonnie to me

[DaveC426913]

Hello, friends.

In my old 2008, my fuel tanks have the quick connect barbed fittings in the fuel lines for Evinrudes. When I top off or disturb the tanks in any meaningful way, the firings will start to slowly leak fuel.

What can be done?

I disconnect both when I return home, but even if I left one connected, the other would still be an issue. I tried looking for caps for the plugs, but that's a hard find. Going someone just has a solution for me.

Thanks in advance!

I just had my hose split in several places. Had to replace it.

But it sounds like you're having trouble at the fittings.
Are they dirty? Poorly fitting?

[OverEasy]

Hi All

The Quick Connect Fittings (QCF) have little O-RINGS inside that actually do the sealing.
They get old and get damaged.
Some will shrink over time with fuel contact.
Some will swell due to fuel additives or ethanol and get soft and them get worn away.

The O-RINGS can be replaced but can be a bit of a task.
GOOD automotive supply store will have a strong fine hook tool to accomplish this.
Replace with VITON material compound to avoid a repeat issue down the line.

Some QCF are physically damaged over time and use or develop burrs or gouges.
Given the size of these things blending of burrs generally doesn’t work out favorably.

It might be best to bite the bullet and replace them with new ones.

Fuel lines….
We replaced ours with new when we changed out to our new 12 gallon tanks.
Bought the grey 3/8 dia from roll stock at West Marine.
Though this is a good product and has only been in use for the pst 18 months we’re going to upgrade to a better type next year.
The hose wall could be stronger as it tends to get pinched a bit too easily.

When we had our new Suzuki engine installed our installer used a heavier gauge black line that Suzuki recommends.
It looks to be much more durable and we are told that it doesn’t scuff and is very UV resistant.

The other option is getting Teflon core SST outer braid fuel lines made up.
This isn’t as difficult or expensive as one might think.
Commercial hose shops work with this all the time and generally can be found in most areas (with a little effort).
The advantage is they don’t collapse, last forever and look sharp!
Addenda Note: IF we were to go this route we’d made sure that the braided lines were not going to be under foot as we wouldn’t want any foot traffic wear to make any loose wire which could lead to an Owwie as we like being barefooted when the weather is nice

Best Regards
Over Easy

PS: We also removed all QCFs from our set up as
1) I’m not gonna ever lug around a full 12 gallon fuel tank
2) the new Suzuki engine, unlike the old Tohatsu, doesn’t utilize a QCF when connecting the fuel line to the engine
3) the QCFs, especially the self sealing type, provide a significant flow restriction.
Addenda Note: 4) we always make sure that there is a sufficient “air gap” over the fuel level in the tanks to ensure that any vapor pressure doesn’t force liquid fuel up into the fuel level gauge wells or up against the fuel feed line fittings on the top of the tanks. Current regulation fuel tanks do not vent off excess pressure any more like the old ones did. The new ones only vent “inward” to prevent a vacuum from forming in the tanks. If there isn’t a sufficient air gap the vapor pressure build-up will force liquid fuel up against the fuel level gauge and fuel feed seals potentially leaking fuel. This tank pressurization effect may also be part of the reason marginal or compromised QCFs may experience leakage.

[Idiotfool]

Hi, all.

I was referring to the male barb quick disconnect fittings on my fuel tanks.

Moeller 033400-10 Johnson/Evinrude Male Fuel Tank Connector - 1/4" NPT https://a.co/d/iL8GyxG

When I fill the tanks, or move them when they're full, the fuel will leak out of these if they're not connected. I don't see where o-rings would go. One side has little ball bearings, so I expect there's a spring plunger or something that's engaged, but I don't know how to take this thing apart.

Overeasy, did you replace with hard lines or flexible? How did you handle both tanks and the squeeze bulb pressurizer?

[OverEasy]

Hi IdiotFool!

We got tired of the Quick Connects that we had originally when we changed from twin 9 gallon tanks to twin 12 gallon tanks.
We used 3/8 diameter flex lines to a an A-B-C tank fuel selector (capping off the currently non-existing ‘C’ tank).
Then fed the common output from the fuel selector to the pressure bulb.
From the bulb we run to a pressure reducing regulator (to prevent excess vapor pressure in the tanks from flooding the engine —- expecially important with the new fuel tank caps that only relieve tank vacuum and not vapor pressure)
From the pressure reducing regulator it runs to a 10 micro fuel filter and water separator.
Then it runs to the engine fuel inlet without a quick disconnect.

While we found that the 12 gallon tank actually hold more like 13.5 gallons but we found it best to limit our filling to no more than 12 gallons. The fuel lockers on our Mac26X are at a bit of an inward slope.
This can sometimes place the fuel level sight gage port at fluid level. When the vapor pressure builds up in the tanks due to sunlight or ambient warmth it would force liquid up into the sight gage port and leak.
Keeping the fuel level significantly below the sight gage port avoids the problem pretty much regardless of active side-to-side angle changes.

There is a picture of what we did in the Mods Section
Macgregor Mods » Motor » Mod to Fuel System (Selector/Filter/Regulator/Primer) for Dual Tanks

When we get back from Lake Champlain I’ll make a diagrammatic and add a better picture of the installed assembly.

Hope this helps some.

Best Regards
Over Easy

[Be Free]

Hi, all.

I was referring to the male barb quick disconnect fittings on my fuel tanks.

Moeller 033400-10 Johnson/Evinrude Male Fuel Tank Connector - 1/4" NPT https://a.co/d/iL8GyxG

When I fill the tanks, or move them when they're full, the fuel will leak out of these if they're not connected. I don't see where o-rings would go. One side has little ball bearings, so I expect there's a spring plunger or something that's engaged, but I don't know how to take this thing apart.

Overeasy, did you replace with hard lines or flexible? How did you handle both tanks and the squeeze bulb pressurizer?

As I recall, the OMC connector had two parts. One was a spring loaded lever just for locking the two parts together. The other was similar to a schrader valve. When the two halves were connected the "schrader-like" part would be depressed allowing fuel to flow. I think there was also an o-ring on the engine side that sealed the fuel in when connected.

I think I may have an old one around somewhere. I'll check and get back to you.

[Be Free]

Ok, I just checked and found I forgot one other part. There is a check valve behind the o-ring on the engine side of the connector. If the check valve spring is weak or there is garbage in it you will get a leak. If the o-ring is dried out and hard you will get a leak. If the "clip" does not engage properly you will get a leak. If you don't push the connector on exactly right you will get a leak. (Are you seeing a pattern here?)

My boat came with a Honda engine but OMC connectors on the fuel line and tank. I got tired of rebuilding and fighting the leaks on the OMC connectors and changed them out for a more modern connector. It works like a high pressure air connector and does not leak! I think it is for a Honda; might be something else. I don't remember. The takeaway is that the fuel line connector has to match the engine on one end and the tank on the other. There is no requirement that both ends of the fuel line be from the same manufacturer. Your tank probably has a 1/4" NPT female connection. It's easy to change.

[OverEasy]

Hi Be Free!

Fully agree with your seeing a pattern thoughts
Sort of why when we made our dual 12 gallon tanks mod and fuel system we got rid of all the QCFs!
One less thing to contend with.

Our 3/8 inch fuel lines offer very little flow resistance (especially with respect to our old 2-stroke) but the new 4-stroke sips gas such that an 1/8 dia line would probably suffice!

Best Regards,
Over Easy

[Russ]

I bought my 2008 Mac from Blue Water Yachts and they outfitted my boat with two 12 gallon tanks with quick disconnects.

This is like the connector on my fuel hose to the tank.


This is like the connector on my tanks


I don't know why BWY used this type of connector, but they have been flawless. I've never owned an outboard engine with separate fuel tanks and assumed this is what they all look like.

Disconnecting them may spill a few drops of gas and they don't leak at all. If I totally remove the fuel line, the line will not leak.

BWY is an excellent resource and I would give them a call and ask them if they have a solution. Perhaps using a different style would solve it.

[Be Free]

Those are similar to the Honda connectors. Slightly different aspect ratio. They work well.