Gas fumes in cabin

[biffdotorg]

I did my searches and all I am finding for issues with fumes is the blowers. So I will start a new discussion. I think I have it narrowed down, but your experiences are what I am here for.

I'm thinking my fuel cell breather or the check valve may have come disconnected. And to fix that, I honestly just need to put my head in the hull and connect it. But what I am curious about is if folks had a way to "check" the check valve or know of other causes of heavy raw fuel fumes in the cabin.

I have my boat on the lift now. And after pulling it out of storage, I topped the fuel tank off with 40 gallons of fresh fuel. After a day on the lift with the snap covers on, the smell of raw gas was strong. I immediately opened up the engine cover and started the blowers in case that may help as well. But also opened all the cabinets and under seat storage to try to find the source.

I looked for pooling fuel in the bilge, and only saw the standard cup of water or so. No fuel in from what I could tell and dipped my fingers in it and it only smelled clean. That made me feel good. So that ruled out the filler neck coming disconnected in my book. But next would be to pull the floor panel over the fuel cell and check connections at the pump and hull.

It's really strong, and I don't feel comfortable boating until I track it down. I suppose there is the chance that the filler came loose and fuel could have gotten in the hull, only to evaporate instead of drain. Again, visual inspection will have to happen.

Anyone else please share anything common I should check. If all looks sound, I may even try to rinse the inside of my hull from front to back with the drain plug pulled on the lift to be sure there is nothing spilled in there. But that would worry me more, making me wonder what may have leaked fuel in the hull.

The only thing petroleum based that would have been in the hull would have been oil from my oil changes in the fall. And a fair amount of that usually misses the dog potty pads I put down for when I swap out the filter. But can oil have that strong of a smell? maybe if it sat over the long winter? Maybe I need to do a simple green rinse of the engine bay, as I do not see anything and thought I did a good job.

Thanks as always.

 

[Babin Farms]

Check the hose clamps on the fill line, vent line, supply & return lines at the tank, maybe one of those finally gave up. Maybe the filler line where it meets the filler neck also.

 

[biffdotorg]

Check the hose clamps on the fill line, vent line, supply & return lines at the tank, maybe one of those finally gave up. Maybe the filler line where it meets the filler neck also.

If I had to guess, those hose clamps may not have been stainless, and coming from saltwater, there very well could have finally given up. I guess it's just time to tear into it and look. I hope it's something obvious.

 

[biffdotorg]

Well, I am happy to report back, that all clamps and connections on top of the fuel cell are in pretty good shape. And other than a little rust on some bolt heads, pretty solid. A couple of those little ones are pretty rusted, but I was unsure what they were actually holding. I could not see the breather hose from the batteries, but could see the filler hose, and again, good looking hose clamps and the breather was still mounted up to the hull. But out of reach.

I could have opened the access panel from the engine compartment, but was just taking 10 minutes over lunch to check it. I was pleasantly surprised that there were no abnormal fumes when I pulled the cover off.

My theory, I topped that tank off with fuel before dropping it in the lake. I covered it and let it set full on my lift for a week before pulling the top. With fuel expansion, etc, there is always a chance fuel got somewhere it was not supposed to in the hot sun. Where, I am unsure, as the breather is the logical choice for evaporation.

Come to think of it, that's the breather on top, front and center. The filler is off to one corner, under the deck. I should go back and check that. I may go back down to the dock in the evening and pull that access panel to be sure. But I am going to call this a freak, as I have never let this boat sit with a full tank of fuel before. It's always fill and start burning.

Ideas are always welcome, but it does give me an excuse to sneak out early today and go fire it up, to truly tell if a cold beer in the boat is still working properly. (I mean, the boat is still working properly while having a cold beer in the boat) or some rendition of that theory.

 

[Russell]

Maybe check that breather vent for leaks where the rubber connects and the fuel filler. I have this very same issue in my 212X .

 

[biffdotorg]

Maybe check that breather vent for leaks where the rubber connects and the fuel filler. I have this very same issue in my 212X .

That's my thought. I need to go back with tools and a better flashlight. As it's behind one of those round access panels in the engine compartment. I cannot get past my batteries to see if from the front. TY

I am assuming the check valve in the breather hose is to keep moisture from going into the fuel cell. I could trace that back, but I think that is under the deck.

 

[anmut]

Take your breather off from the top of the tank, push a wire through it to make sure it's clear and clean and no insects made a nest in it.

 

[biffdotorg]

Hmm, there is still screen on the vent cap on the outside of the hull, and the check valve in the middle of that hose. So if anything, they would have had to come from the hull size I think. More inspection is needed for sure. TY

 

[biffdotorg]

These all look good, and the fumes were not bad at all this morning when I uncovered the boat. This one puzzles me

Here are photos of the breather outlet inside the hull, and where the check valve is zip tied in the engine compartment. Glad to have taken the time to find that. Not sure, maybe the check valve is not allowing the tank to breath and fumes are being pushed out somwhere else. With a full tank, and warm weather, I would bet that pressure could be strong.

 

[Babin Farms]

Give the check valve a few taps with the handle end of a screwdriver in case it's stuck.

 

[biffdotorg]

Good tip, will do. Other than replacing it, I was unsure of how to test it without pulling it out. Of course it's so easy to get to leaning over the engine compartment, and down to the access panel and then back inside.

 

[Scottintexas]

In the spring with a full tank and the boat cover on many times I come out to find the cover saturated with fuel at the vent,

I've seen other members report this happening also and just chalk it up to heat expansion, I stop filling at the first click now,

 

[Julian]

It might have been expansion overflow from filling it with cool gas station temp gas, then sitting it out on the lift in the sun. This is why I bought and installed a fume detector. It has gone off twice while fueling....both times while in the water with a breeze from the filler side (fumes were blowing into the boat while filling and triggered the alarm).

 

[TimW451]

I put ~52 gallons of gas in once, and then I had a very strong smell of fumes the next few times I uncovered the boat. So, I don't do that anymore. I did just replace the external vent as it was very corroded, but can't say if it has reduced fumes. My motivation for replacing it was the gas pump shuts off too quick when I'm filling up. Hope it fixes that. I'll have to look for a check valve on the vent line I don't recall seeing one in the storage compartment (that's where it looks like yours is).

 

[biffdotorg]

I'll have to look for a check valve on the vent line I don't recall seeing one in the storage compartment (that's where it looks like yours is).

I actually was not able to see mine until I took the round access panel off in the engine compartment on the Port side. And still then, it was inside that compartment between the batteries and the engine bay.

Sounds like my biggest mistake was filling the boat and not burning the first 10 gallons out, like I usually do. Shame on me.

Thanks again for all the replies guys. It helps get the brain working!

 

[Russell]

biffdotorg,

Are you satisfied with this non-fix issue? Have you replaced your checked valve? I did find a thread on the other Yamaha site in which the a member found a leak around his port side fuel pump. He ended up using a caulk to seal the leak and thus solved his vapor issues. I've bought a new gas fuel filler and fuel vent for my boat. I'll probably grab some tank fuel pump gaskets as well. I'm curious as to where you stand on this issue.

 

[tdonoughue]

I agree from the thread that this was probably a case of overfilling.

However, I feel the need to offer a PSA: Gasoline is not very flammable. Gasoline fumes are extremely flammable. Common misperception is that a pool of gasoline is dangerous as an explosion hazard. In reality, the pool itself is relatively harmless. The VAPOR forming over the pool, however, (from the gasoline evaporating) is extremely dangerous and can be set off relatively easily with very negative effects (boom).

Upshot is that if you smell something, that is much more critical than a pool of wet that you may see. Make sure you vent and have your blower going until you have that all cleared off and smell nothing. Please.

 

[biffdotorg]

biffdotorg,

Are you satisfied with this non-fix issue? Have you replaced your checked valve? I did find a thread on the other Yamaha site in which the a member found a leak around his port side fuel pump. He ended up using a caulk to seal the leak and thus solved his vapor issues. I've bought a new gas fuel filler and fuel vent for my boat. I'll probably grab some tank fuel pump gaskets as well. I'm curious as to where you stand on this issue.

Yes, i think I am satisfied. As this is the very first time the boat has sat that long on the lift with a completely full tank of fuel. I have pulled the floor panels and access panels and have checked every fitting for seal other than where the fuel filler hose hits the fuel cell, as it’s difficult to see.

But with each time that I have gone down and pulled the cover, the less and less I notice any fumes. I am to the point of not worrying about the issue anymore. I may order a check valve, as I am certain that is an inexpensive part. We will see.

And yes, to the point that fumes are more dangerous is correct. But the fumes have to come from a source, and the source is what is bugging me. My engine bay really has never had much of a raw gas odor to it. And I am religious about opening the engine bay before anyone gets on the boat. As once someone is in, they bitch about me having the engine cover open. To which my reply is “you should be happy I opened the cover, rather than it blowing open by not doing it”

 

[FSH 210 Sport]

Biff,

A couple of questions.

1-Did you fill your boat up with gas at a fuel pump? Or did you fill it with gas cans?
2-If the answer to question one is yes, did the pump handle feel cold in your hand?
3-Do you think you may have over filled the tank due to too many clicks of the pump handle?
4-Does your boat cover go over the fuel fill and vent ports?
5-I did not see it in your pics, does your fuel vent line have a charcoal canister in addition to the check valve?


I recently had some faint gas odors in my boat where there hadn’t been any ever. And I believe it was after I had filled it with fuel that I started to notice this.… it’s been a while since I noticed the fumes.

1-If you filled your tank with gas cans, it can easily be overfilled. I say this because you talk about taking it out of storage and being on a lift… just want to be clear.

2-As @Julian mentioned, cold gas (you are in MN after all) from a gas station tank will expand a lot when it gets warmed up. I would add that if you filled it to the very top with cold gas, the expansion of the fuel is going to cause the fuel to go places it normally wouldn’t if there was a gaseous place in the tank for The expanding fuel to go to. As @Scottintexas mentions about his cover being saturated at the vent in spring due to expanding fuel, not sure if his year boat has a check valve on the vent or if it’s a free flowing vent.

3- See #2 above.

4-If the cover is over the fill and vent the fumes will get trapped under the cover.

5-If the vent line is full of fuel, the check valve in the vent line is now submerged and will keep the now building pressure from the expanding fuel from passing out the vent. That means it has to go somewhere and the fuel fill is the most obvious place to go. Did you by any chance pop open the fuel fill cap to see if the gas was right there?

As @Scottintexas mentioned about his external vent being corroded, you may want to pull the vent and see what tge condition of it is.

Hope this helps!

 

[TimW451]

....
4-If the cover is over the fill and vent the fumes will get trapped under the cover.
...

I was thinking about this the other day. I have the Yamaha mooring cover, which covers the vent. That is kinda dumb. Logistics might be a b*, but that probably should have a hole or screen there.