Seafarer Viking Leaking Petrol

[john Meli]

Has anybody had a problem with leaking petrol from the fuel tank breather pipes in hot weather. If so any ideas on fixing the problem. John M.

[Noelm]

I guess the breathers must be too low, tank too full or something, a breather is a pretty simple thing, just a pipe on top of the tank and a hose going to the outside, so unless it has a really low spot in the hose and it has got full of fuel, or there is some other obvious problem, like parked on an angle with a full tank, then it must be something really odd.

[Ocean_Spirit]

As Noel said, angle of the boat will affect it.

The breathers are mounted in the transom? Run an eye from the breather to the actual tank mount and check for any irregularities. How full is the tank?

[Jabba_]

John I also get a bit off fuel over flow out off the breathers from my Seafarer, but only if it is 100% full and sitting on an angle...

how bad is this fuel leak, can you put the boat under any shade to reduce the heat on the tank.
It is also possible, that you may have a blockage or kink in one off your breathers.....

[walruss]

John Have had the problem with my last 2 glass boats. Only hapenned when the tank was near full and the weather quite warm. was told by a wise old one that it was caused by the build up of pressure in the tank. As a result all i do now is leave the fuel cap just loose so that no pressure can build up, also eliminates a vapur lock that may happen and all is no Ok. Haven't had a problem since.

Russ

[Noelm]

the breather is the same as leaving the cap off, that's why it is there, your tank must have had a loop in the hose or something and it got full of fuel, as the tank pressurises, it forces some out!

[Chimo]

Hi John M

If the leak is out of the breather outlets on the transom as the guys have said, dont fill so full esp. in hot weather; drop the jockey wheel to take the pressure off: keep the boat / tank cool ie shade (shed, carport, tarp with air flow!)

If the leak is in the boat and you think its the breathers and you have a SS tank
check the tank is not sitting directly on fibreglass ie there are teflon spacers under it. Pinholes can develop under the tank due to water and electrolysis and the first sign of trouble is when pressure builds up in the tank and fuel appears at the back of the boat. I had this happen to me as the tank was "mistakenly" installed without spacers. Took yrs but it will heppen!

Cheers
Chimo

[john Meli]

Hi John M

If the leak is out of the breather outlets on the transom as the guys have said, dont fill so full esp. in hot weather; drop the jockey wheel to take the pressure off: keep the boat / tank cool ie shade (shed, carport, tarp with air flow!)

If the leak is in the boat and you think its the breathers and you have a SS tank
check the tank is not sitting directly on fibreglass ie there are teflon spacers under it. Pinholes can develop under the tank due to water and electrolysis and the first sign of trouble is when pressure builds up in the tank and fuel appears at the back of the boat. I had this happen to me as the tank was "mistakenly" installed without spacers. Took yrs but it will heppen!

Cheers
Chimo

Thanks Chimo, There's no kink in the breathers, Ive actually put a big loop in the breathers. This has helped but I still get the smell of fumes. I do have the boat in a shed. I'll try not to fill so much lower the jockey wheel and loosen the cap and see how it works.

Thankyou John M

[Noelm]

A loop in the breather can be a very bad thing!! what happens is the Boat bounces around, the fuel gets "shoved" into the breather hose, a bit at a time, and in the end you have the bottom of the loop full, (and blocking off the air) and when the tank pressurises, it forces the fuel around the loop, and possibly out the breather!

[Chimo]

Hi Noelm

In this case, as its a Seafarer, and we know that Seafarers don't bounce around esp. with Evinrudes or even Etecs so there may not be much of an issue with a looped hose! Mind you I agree that a breather is better to be "loopless"

Cheers
Chimo

[Hornet Rider]

Hi Noelm

In this case, as its a Seafarer, and we know that Seafarers don't bounce around esp. with Evinrudes or even Etecs so there may not be much of an issue with a looped hose! Mind you I agree that a breather is better to be "loopless"

Cheers
Chimo

Chimo, I met a very sweet girl, many many moons ago of course, who could best be described as 'loopless', but there was nothing wrong with her breathing, as I recall. :-*

Guess what :) gave me for Christmas? A nice new fuel tank for the Express. Got it off Phil this arvo. Quality craftsmanship...... pics are at this thread.... http://www.ausfish.com.au/vforum/showthread.php?t=142915&page=2

cheers, HR ;)

John M, hope your leaking fuel issues are a thing of the past.

[Darren J]

Hi all,
I have a 91 model Viking and found the same problem. The breathers are at the top rear of the tank and have a single line (no loops) to the breathers. Mine are mounted highish in the rear motor well.
My boat is stored outdoors, with full cover but gets a fair amount of heat. When the tanks are full, and the jockey wheel up enough to keep the front of the tank high (which happens even when wound right down) any remaining air in the tank sits to the front top, thus the overflow lines are fully submerged. of course not much expansion is needed before fuel begins pushing out of the breathers rather than air.
The loops would make no difference except to give a little more length before the fuel pushes out. If you did have loops fuel shouldn't slosh into these at the higher level, but still they really should not solve the problem of leaking from the breathers. I agree better loopless.

i learnt this the hard way after the boat was left full for a week, and jockey wheel wound up high. It took about 35 litres to re-fill the tank!, all gone down the gutter.... Lucky no passers by tossed a cigarette.

Only solution is as the other guys have suggested is don't leave it parked full (not very practical), or if you do have it filled crack open the filler (mine is toward the top front of the tank) So that air can bleed from there rather than force fuel out the lines. I would assume this problem would occur on any boat with similar proportioned tanks and set up.

Cheers.

Hope this

[Mr__Bean]

the breather is the same as leaving the cap off, that's why it is there, your tank must have had a loop in the hose or something and it got full of fuel, as the tank pressurises, it forces some out!

Gunna differ with you on this one Noel, if the breather pick-up within the tank is submerged in fuel due to fill level or boat angle then loosening the fuel cap can provide an additional source of tank breather and prevent the tank blowing fuel out of the breather as it heats up and the fuel/vapour expands.

Makes no difference if the breather pick-up is already above the fuel level but if below then it does help mine stop blowing fuel out.

- Darren

[Chimo]

Nice tank HR , also posted to the other thread.

c
Chimo

[gofishin]

I have a 91 model Viking and found the same problem. The breathers are at the top rear of the tank...not much expansion is needed before fuel begins pushing out of the breathers rather than air...I would assume this problem would occur on any boat with similar proportioned tanks and set up…
Unfortunately there are many boats around with a poor fuel system design such as this, and Darren J is correct. Most people with any sense store their boats in a bow up attitude so that any water drains out of the bungs/scuppers. Pretty poor when this causes a fuel vapour lock when your tank is near full, causing fuel to pi$$ out the breather.

With the above system, and if the filler is mounted at the front and the top of the tank, cracking the filler open will help as it then acts like a breather (as Mr Bean has said). However, if the tank is too full to start with, and you get a sufficient fluid temperature rise, you could end up with overflows from both filler and breather if they are at an equivalent height (ULP has a fairly high thermal expansion ratio). The problem will compound significantly in a tinny if fuel overflows out of the filler and into the boat - big problem with EPS foam under a non-sealed floor, not to mention glued-on carpet on the floor in both tin and some glass boats!

Quite a few years ago one tinny manufacturer had a major recall of boats with fuel system problems that could lead to vapour locks and resulting spills from expanding fuel!

Loops are 'old school thinking’; when it was thought that they reduced moisture problems within a tank due to condensation. They don’t. Loops, or even sags in the breather line (from poor installation technique/process) get fuel in them when you fill up, from use, or from thermal expansion. The small amount of fuel within a loop prevents the breather from working like it should in an open system, and creates either a +ve or –ve pressure within the tank depending on thermal changes, or if the tank is being used etc. Basically they prevent an open fuel system working like it is supposed to.

John, if I had your boat I would ditch the loop, swap the filler cap assy for a USCG model that allows vapour release (breathing) but not liquid overflow, never fill my tank beyond 90-95% (if I were storing it with a full tank), and always store it with just enough nose up (for drainage), but not too much so as to possibly cause fuel problems. Actually, with today’s ‘enviro friendly’ fuels, it is best not to store tanks full at all, especially for more than a few weeks. 1/3 to ½ max is better, then top up with new fuel on the day, just before your trip etc.

FYI…in Oz we have no mandatory regs regarding fuel systems in rec boats, and we are decades behind US and EU mandatory regs, and from many other nations that have adopted similar regs many, many years ago. From memory US regs require fuel systems to be designed with a 10% expansion allowance when the tank is full, or the equivalent to allow a 20 or 30 (??) deg temp rise, ie. to prevent fuel spills due to thermal expansion. With the design of these tanks, it is virtually impossible to overfill the tank, ie. Into the expansion chamber. In addition, the deck filler arrangement must be such that a spill into the boat cannot occur with a certain overflow rate (i.e. during filling).
Cheers & Merry Christmas