Bad gas? Water in gas?

capt-pete

Seaman Apprentice
Joined
Jun 10, 2009
Messages
48
I have 2 six gallon tanks, one of which the boat runs great on all of the time. Not so much on the other. Sometimes it seems to run fine, but other times it just bogs down like it is choking for gas.. when I feel the primer bulb, it is full of gas, and have checked to make sure the pressure valve on the cap is open... so it's not a fuel delivery issue (I dont think)...

I guess this is a long winded way to ask the simple question.. Now that I have it full again, and have yet to run it all the way empty, if there is water in there, if I put the additive in the gas to get rid of it, is that bad for my 2 stroke engine? I would hate to throw out 6 gallons of gas, and wouldnt have the slightest idea of what to do with it anyway.

other suggestions? thanks!
 

marine4003

Lieutenant Junior Grade
Joined
Feb 3, 2008
Messages
1,119
Re: Bad gas? Water in gas?

Depending on the age of the motor..it may be time for a carb rebuild..after a while floats get stuck resulting in fuel starvation,jets get clogged...read Tashadaddys advice on carb rebuild's,if you burn thru the gas within 30 days,its improbable its the fuel.
 

capt-pete

Seaman Apprentice
Joined
Jun 10, 2009
Messages
48
Re: Bad gas? Water in gas?

Just had everything cleaned and rebuilt.

It's a new boat to me, but an older 1978 Thundercraft with a 80hp mariner, so I had it gone through really well before I took it out on the water.

It only happens on that one tank, and once I switch back to the other tank it runs flawlessly (after it runs through the "bad" gas from the other). I have run that tank down to a gallon out of 6, 2 times now though, and would think the problem would go away. Today it was worse than ever. Last time, it bogged down, i waited a few seconds, and then it ran fine. Today, it wouldnt do more than idle on that tank or that tank's gas. Once I switched back to the other tank, it was fine again in just a minute or two. Then once I had it running strong yet again, I tried switching over, same problem. Water in the bottom of the tank getting stirred up I guess?

Any way to get it out without having to find a place to dump 6 gallons of gasoline?
 

marine4003

Lieutenant Junior Grade
Joined
Feb 3, 2008
Messages
1,119
Re: Bad gas? Water in gas?

I'm not familiar with the boat..are the tanks portable? if so use the gas for your lawn mower...'cause it definitely sounds as if there's trash in the bottom,and continuing to use will foul the carb.it sucks wasting $15 in fuel...but its cheaper than damaging the motor.
 

P 0 P E Y E

Chief Petty Officer
Joined
Jun 3, 2009
Messages
441
Re: Bad gas? Water in gas?

I am assuming you have 2 portable 6 gallon tanks...is this the case?

It runs good on one tank and bad on the other. Are both tanks the same? There are a whole bunch of different tank quick disconnect fittings that look very similar but are not the sane.

Are both the tanks in the same position relative to the engine?

If it was water in the fuel causing the engine to fail, the water would still be in the engine.

I would take a good look at the suspect tank. inspect the quick disconnect fitting it may be different than the good tank or wrong for the hose your using.

Take a flash light and look into the tank through the fill hole and see if there is a layer of water at the bottom. Tip the tank so the lowest point of the tank will be directly below the fill hole.

The fuel pick up hose in the tank may have come off or have a clogged end. If none of this helps try switching the caps to see if the problem is the cap.

Take a look at everything to do with the bad tank to find the fault.
 

gss036

Commander
Joined
Jan 18, 2003
Messages
2,914
Re: Bad gas? Water in gas?

Are you using the same hose on both tanks? If so, switch hoses. It sounds like you are sucking air somewhere from the fittings. Like Popeye says, look at the fittings, check the "O" rings, maybe a little Vaseline of them.
 

onthelaketwo

Cadet
Joined
Jun 6, 2009
Messages
7
Re: Bad gas? Water in gas?

Getting rid of old gas is tough.

Check your state EPA. In Illionis two sites in state take the gas for free, one in Rockford, and one in Naperville.

many cities have one day a year they take bad gas.

I filter mine with Coffee filters, per instructions from Web. I than gave it to a guy with a gas power backhoe. He mixed it 5 parts new gas, 1 part old gas.

That how I got rid of 5 gallons.

Good luck,
 
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