Can someone tell me what is happening to my gas

I have a 20 ft center and it was stalling on me so i changed out water fuel filter and other filters and pumped out some gas in to a bottle and it looks like my gas it in 2 parts and after it sets for a few hours I see 3 parts to it ?

 

how often do you run the boat and when was the last time you totaly filled and emptied the tank?

 

i run the boat pretty often, the last time was maybe a week ago. i have never let the gas tank get completely empty, i try to keep it at half a tank or above.

 

It is unlikely the motor will run on the heavier component that is sitting in the bottom of the bag. I expect you will find it is H2O.

Have you checked the breather or had the boat out in the open with the fuel tank cap ajar?

Other option is your fuel supplier has had his tanks flooded and you have been buying more than fuel.

Suggest you drain the lot and remove the heavy portion. Also your filter should be fouling up quite quickly.

If it is not H2O then I would be very interested to know what it is.

Rick W

 

Actually there is another thread talking about ethanol in your fuel in the USA. Ethanol has a slightly higher density than gasoline so you may find it is ethanol that has settled out.

Also ethanol has a significantly higher flash point than gasoline so it will not be real good at a cold start.

If it is ethanol it has settled out over time and you are probably getting mostly ethanol when you are trying to start.

Again, drain the tank, remove the heavier component and refill with the lighter component. Drain the lines so they fill with fresh fuel. Remove a plug and dose it with fresh fuel before refitting if it does not fire after a few cranks.

Rick W

 

What Rick said ...

and by the by...

You can put a little metho in your tank every so often to pick up any water that is there, only small amounts obviously. A decent water trap is prolly preferable but the metho picks up the scraps. I always ran a CAV filter so that I could see what was getting to the engine.



http://wiki.answers.com/Q/Does_adding_methylated_spirits_remove_water_from_petrol

 

Got it

I jacked up the front of the boat. Then opened the gas tank where the fuel gauge is and sucked out about 10 gallons of gas in to gas cans . Then I put new fuel water filter with the see through bottom with drain. I use Sta-bil ethanol treatment marine formula. Is that enough additives or do I need to add or can I add metho ?

 

Pic of the gas

Here is a pic of some more gas and top and bottom layers

 

It Is Fixed

Thank you guys for your help !

 

I have no idea! The metho thing was just an occasional maintenance measure to mop up what ever condensation etc was lurking in the tank, an old pilot sailor friend told me about it when I had a yacht with a 2 stroke inboard and a metal tank that was prone to gathering water. It's always worked for me... that's all I can say!

 

Yes, as Rick said a tank breaths, and it breathes more with more head space so keeping the tank full (i.e. fill it up after a days running) will prevent pulling water into the tank. I don't know how your tank is set up, but usually the fuel pickup is up off the bottom so any water or debris settle below the pickup and can be drained off occasionally.

Even so, fuel filters with seperators are always a wise choice. I like to plumb a pair in parallel on any boat that will be going offshore, so you don't have to shut down if stuff gets stirred up and clogs the first.

The methyl alcohol (i.e. "Dry Gas" and the like) is totaly soluable in water and in sufficient quantities relative to the water (i.e. slightly more than 50/50) will allow the alcohol-water mixture to "burn" in the engine. Not really good to run on for long, but mixed in with gas will keep the engine running and pure water from pooling the carb bowl.

 

Well,

I don't know if your aware in Florida all gas now contains 10% ethanol. That means it will evaporate faster, give you less power and absorb more water So keep gas newer, don't let it sit as much as before. I have same problem with one more difficulty. My gas boat is a 2 stroke with oil premix. It is driving me crazy because I put in right amount of oil use boat everything fine. Then leave tank at 1/2 come back next week, tank is at 1/4 now there is too much oil. So I add gas, but it won't mix right.

 

"i have never let the gas tank get completely empty, i try to keep it at half a tank or above."

"and it breathes more with more head space so keeping the tank full (i.e. fill it up after a days running) will prevent pulling water into the tank."

Both these methods are fine for diesel, and WERE fine before the gas got Ethanol.

Today the more fuel in the tank, the more ethanol, so the bigger the problem.

Any unused fuel will pull moisture out of the air and eventually water and ethanol will fall to the bottom of the tank.

With todays fuel run the tank as low as you dare at the end of the day leaving only enough to get to the gas dock for the next use.

YES,, this backwards from 100 years of experience, but Ethanol sucks in fuel, and is there only for political reasons.

Your mileage drops by more than the percentage of Ethanol, so the gov gets a huge windfall with 10% dilution they get 10% to 15% more in gas taxes , all without ever voting for a tax increase.
And they can posture as GREEN, not tax men.

Portable tanks offer one solution as you can run the built in way down and have an accurate method to get home.

Any fuel for an outboard should just be added to the family car , at the end of the weekend.

A second but expensive solution is to purchase the fuel at the local small airport. Aviation fuel does not yet contain Ethanol , and can be stored for months , if not yet mixed with oil.

FF

 

With petrol I make a habit of switching the fuel off at the tank and running the system dry when closing down. I find with the outboard I am running now it makes starting a lot easier with fresh {ish} fuel from the tank, I don't know about big inboards --> prolly a reason that is bad?!