Strong gas fumes after minor haulout joltng

[ArtJ]

Yesterday I hauled out my Tartan 34c on the club's Brownell Trailer
The gas was filled and stabilized a few days before.
The engine started well yesterday and ran well all season with a new carb and filters.

When after adjusting stands i went below to the cabin and smelled strong
gas fumes.
I am thinking that jolting during haulout may have stuck the
carb float or less likely, the very full tank sloshed out somewhere?

The fuel was left on during haulout and only shut off an hour or so later
when closing up the boat.

The fumes still remained this morning

I have had stuck floats due to fuel last 'season, but never this season
or so abruptly have yet to investgate

Suggestions appreciated.

[Al Schober]

Check the hose between the deck fill and the tank. Mine just crumbled in my hand. Easy fix - thought I had a leaky tank.

[capnward]

Investigate with power off and boat well ventilated. Check the bilge with your nose. Really strong gas fumes are probably not just a stuck float valve. It could be something like a loose hose fitting above the tank which only leaks when the tank is full. Jolting on the trailer is not likely to create a new leak. Do not start the engine before checking for fumes and fixing the leak. If you can smell gas fumes anywhere but at the carb air intake, it is serious.

[JOHN COOKSON]

MY 1st QUESTION

Is gas pooling in the carburetor throat?

ex TRUE GRIT

[Mo]

Hi Art,
Had a friend with a Tartan 34. If I remember your engine is in the middle of the cabin beneath the floor boards?? Any sign of gas in the bilge? All good suggestions the guys have mentioned.

[jcwright]

The engine in a Tartan 34c is indeed in the cabin, but not entirely beneath the floor boards. When the engine enclosure is closed, the blower pulls air through the bilge from a vent in the forward chain locker. But, when the enclosure is removed the blower draws mainly from the bottom of the standpipe rather than the bilge. As Art may have experienced, if there is fuel under the engine or deeper in the bilge, the blower can't clear the fumes effectively when the engine cover is off.

Jack.

[ArtJ]

Thanks for the replies guys much appreciated
I have had a stuck float last season which loaded the bilge with a qt of
gas before detected. Flushing the man passage fixed that then.

This time filled the tank on Wed hauled Sar. Ran fine to dock where
t sat 4 hrs waiting my turn to haul - fuel was left turned on -was not sure
of haul out ordering.

fuel accumulate could have started then.
On these boats fuel can gravity feed when facet is off and potentially empty
tank into bilge. Too bad facet does not include a fuel shutoff option
as well as shutting itself off.
When done using boat for day always shut off the manual valve near tank
Th odor was there yesterday after overnight, but not as strong.
Normally would have checked bilge then but live 50 miles away
after helping other boats haul was xhausted. will go tomorrow
and report findings
Thanks best to all
Art

[brewgyver]

Might be worth considering adding fuel stop cock at the pump inlet. Less desirable option might be to add a normally closed solenoid valve.

[zellerj]

My 30 something aluminum fuel tank had pin holes that slowly leaked gas. Have you checked the bottom edges of your tank for corrosion?

[ArtJ]

There s a fuel shutoff at the input to the pump but when running the engine
periodically during the day it would be open except when done for the day.

I wonder if a safety in line solenoid would be a valuable safety feature when engine is off?
but that would not help for a stuck float while the engine is running
However, it would still be a worthwhile safety feature

Pinholes would be showing up all the time, not a quick rush of fuel like this. besides have a ss tank that is not too old

Thanks

[Mo]

Al, I think I know how your boat engine is situated. My thought would be an easily accessible shut off very near the engine....it's gravity feed for the most so I'd have a little door there in the cover somewhere...slide it open and open the shut off valve "you just installed'....right there near the engine. I'd even consider a loop to make the pump have to do it's job and sort of prevent seepage.

I'm writing this part for the new people in our forum. We should ALWAYS go in the boat when we get aboard. 1. we either smell gas or we don't. 2. It really doesn't take gallons of gas to create fumes in warm weather...flash point ratio. If you smell gas it's fumes can flash/ignite with a spark. Gas has been known to flash at -40 F or -40 C...that's significant.

Al, wishing you all the best on this and I'm sure you will sort it out .

mo

[ArtJ]

Problem ID'D

was at the boat today
The only leak found was very minuscule amount of gas seeping around the gauge gasket located directly to the top of the ss gas tank located under a settee .
I tightened the screws around its gasket. Plan to add some Permatex around the gauge. Can't remove it due to very full tank.
The gauge is a circular needle dial type - similar to those found on outboard tanks
Every where else was bone dry - hoses, clamps, bilge, vents, fill hoses, fittings

Thanks Best to all
Art

[Mo]

FWIW Seal-All works good around gas. Small leak..works great and once set up not affected by gas.

[ArtJ]

Might be worth considering adding fuel stop cock at the pump inlet. Less desirable option might be to add a normally closed solenoid valve.

A solenoid controlled valve would be excellent for engine off on during a
day of use. The manual shutoff good for longer over nite protection

Maybe a solenoid project idea for Neil ??

[ndutton]

Maybe a solenoid project idea for Neil ??

Easily done without exotic engineering:

https://www.amazon.com/Electric-Solenoid-Normally-Solid-U-S/dp/B00APDNPXG

However, consider that it is another potential failure point for reliable engine operation and frankly sounds like a work-around of the real problem, why is the fuel leaking in the first place? While a shut off solenoid valve will work, my advice is to deal with the problem directly.