Recommissioning the Fuel System - Should I Mix New Gas with Old?

[Scubaseas]

Originally Posted by Chotu

Yeah. That wouldn’t make sense. You’re right. I think was recalling it incorrectly. I have these:




https://www.greatlakesskipper.com/pe...RoCnUcQAvD_BwE



The confusing thing to me is this thing has a rubber o ring all the way around the round mouth that seals off the whole neck. And the vent is in the neck. So how does the air get in and out? The cap doesn’t appear to be able to allow air in and out. But yet I guess it must.

Pressure relief and vacuum break are in the cap. Your gas is OK due to having this kind of system where volatiles are not vented off to air unless under pressure or vacuum exceeding cap pressures. Works just like a car except you are not recycling the vapor into the engine or having a charcoal canister for over pressure venting.

Keep in mind if you ever have a fuel supply issue open that tank filler cap and see if that solves the problem before digging into other components.

[Chotu]

Originally Posted by Scubaseas

Pressure relief and vacuum break are in the cap. Your gas is OK due to having this kind of system where volatiles are not vented off to air unless under pressure or vacuum exceeding cap pressures. Works just like a car except you are not recycling the vapor into the engine or having a charcoal canister for over pressure venting.

Keep in mind if you ever have a fuel supply issue open that tank filler cap and see if that solves the problem before digging into other components.

Thank you! Will do!

The higher end Facett lift pump (from a different thread) is working extremely well. I could tell by the way the fuel was delivered to the hose I used at the end of the system to fill the sample jar.

Instead of a few splashes here and there with lots of air, like the old pump had, a steady stream of solid gasoline came out.

Hooking up the generators tomorrow and testing it all out with the new/old gas.

[Benz]

Another vote for not using gas with ethanol in it, ever. After taking apart and rebuilding my outboard's carburetor countless times because of the watery shwag they sell in central america as gas, and the ethanol-loaded stuff anywhere north of Virginia (somehow south of there there's lots of non E-10 available), and replaced the fuel hose which was completely buggered up and delaminating inside from the E10 (which eats fuel hoses--you might want to check yours), I only use high-octane, and I make sure it's fresh.
And I long for a gas station that will sell non-ethanol again...

[Chotu]

Originally Posted by Benz

Another vote for not using gas with ethanol in it, ever. After taking apart and rebuilding my outboard's carburetor countless times because of the watery shwag they sell in central america as gas, and the ethanol-loaded stuff anywhere north of Virginia (somehow south of there there's lots of non E-10 available), and replaced the fuel hose which was completely buggered up and delaminating inside from the E10 (which eats fuel hoses--you might want to check yours), I only use high-octane, and I make sure it's fresh.
And I long for a gas station that will sell non-ethanol again...

I know what you mean!

I was horrified up north this summer when I tried buying quality marine gasoline in several harbors, only to find all they sold at the fuel dock was ethanol fuel.

I ran it, since there wasn’t a choice, but I wasn’t happy about it.

So far, down here, no ethanol has touched my tanks.

[wolfgal]

lots to learn here!

i see that you got through this Chotu (with lots of great advice)! really glad for you. and by the way, so glad you resolved the window-saga issue too!

anyhow, if ever you are looking for someone who will take bad fuel/gas, i would suggest to ask engine mechanics. they can either polish/filter it or not, and in any case can usually use it.

[rslifkin]

Personally, I don't get the ethanol fears. Most of the issues with it come down to a few things:

• Either dirty tanks that get cleaned out by alcohol and clog filters.
• Or non-alcohol compatible hoses and seals that fail after exposure to ethanol.
• Or you manage to get enough water in it to cause separation.

All of these are easily avoidable problems. FWIW, my boat ran for 15 years on nothing but ethanol gas when it was in CT. Some fuel lines had to be replaced for compatibility, but they were due for replacement due to age anyway. And other than those fuel lines, there was never an ethanol related fuel issue. Even with ethanol gas, the first portion of the season was burning last year's gas, as it was always stored with full tanks.

I've also burned 12+ month old stabilized ethanol gas in cars with no problem (stored in a fairly well sealed modern fuel system). That said, I do avoid ethanol for my lawn equipment at home, but that's mostly because I have a lawnmower that's jetted a little on the lean side, so when you add ethanol on top of that (requires a slightly richer mixture) it doesn't run quite as well. None of my other equipment cares though.


As a note on the gummed up and corroded carbs thing, I make a point to flood every engine I store for more than a month or so with fogging oil at shutdown. The inside of the carb being all oily seems to do a good job of preventing things from corroding or gumming up, as I never run them dry and have never had an issue the next season on startup.

[Carl-T705]

What... Your talking 15-20 gallons , 5-6 years old. , draw it out and dispose of it. Fuels aren't refined with an indefinite life cycle. Beware that stuff will be very smelly, 6 year old fuel in a vented marine environment is trash.

[Chotu]

Originally Posted by Carl-T705

What... Your talking 15-20 gallons , 5-6 years old. , draw it out and dispose of it. Fuels aren't refined with an indefinite life cycle. Beware that stuff will be very smelly, 6 year old fuel in a vented marine environment is trash.

I guess you didn’t read the thread? Turns out you were wrong here.

We did some really cool testing on the fuel, and it passed. Mix the new fuel in and it’s running just fine.