Potential problem with stale fuel

[Nautical]

Why would you post this on a thread that says the fuel is years old?

Educational purpose only..while on the subject.. Could help others !!

[99yam40]

but it does not help with the OPs question,
and it may confuse him thinking he can fix bad fuel

[rodbolt17]

the biggest drawback to running trash gas in a two stroke?
it laquers the piston with this shiney black coating.
this coating builds up until the .001-.003" piston to wall clearance is no longer there.
that's when the piston comes apart.
I have one downstairs I took apart last night that did it.
if I can figure out pics I will post them.
it will happen to 4 strokes just not as fast.

[Nautical]

[QUOTE=99yam40;112715]but it does not help with the OPs question,
and it may confuse him thinking he can fix bad fuel[/QUOTE
I think it is pretty clear as written. It may not be confusing to him at all, and may not be confusing to others as well. I would let the OP decide if its confusing , but I am sure he appreciates your intervention and concern. As quoted by Boscoe:This website is not about telling folks what might be possible. It is about offering suggestions to help folks have less problems along the way in the world of boating.

[Nautical]

the biggest drawback to running trash gas in a two stroke?
it laquers the piston with this shiney black coating.
this coating builds up until the .001-.003" piston to wall clearance is no longer there.
that's when the piston comes apart.
I have one downstairs I took apart last night that did it.
if I can figure out pics I will post them.
it will happen to 4 strokes just not as fast.

That would make sense..If using trash gas chances are the the octane would be much lower than engine requirements. This could result in excessive detonation which could create higher combustion chamber temperatures in turn would caramelize the trash and deposit it on the piston and wall .. seems logical .

[bajakeith]

Old Gas

This not a debate.....dump the old fuel and start the season with fresh gas.."soltron or lucas" additive seems to help the best with E gas,,BUT two year old gas is suicide for your motor...I see E/gas issues daily and your welcome to watch about the only you tube vide that I seen to date in regard boat repair is the one with a boat mech and a clear jar of "E"gas in front of a fan....its so bad that the gov wont let it be sold at small airports...WHY ?? because the planes would be falling out of the sky !!

[robert graham]

350 gallons at 2 year old marina prices maybe $1000....potential engine damage/repairs$$$ from using this old degraded fuel possibly Much more$$$
Best to dump/dispose of the old gas and write off the loss to experience...

[RayBersch]

Ryan Carlyle, BSChE, engineer at an oil company
If it is airtight in a clean, stainless steel container with little oxygen, and is periodically stirred, gasoline will last a very long time. Many years, if not indefinitely.
https://www.quora.com/How-long-does-...aled-container

For those who do not follow the link and wonder what the hell CapSolo was thinking here is a quote lifted from the referenced engineer's posting:

The problem is that gasoline is never stored in that kind of container, so it does go bad. Various compounds react with oxygen, or get digested by microbes, or absorb water from the air, or whatever. Lots of things can go wrong and additives can be used up just by sitting there. What really kills gasoline, though, is changing weather.

Cycling the environment from hot and humid to cool and dry will allow moisture in, and vapors out. Over time, the lightest components will evaporate off and the average molecular weight will get heavier. This will make the fuel harder to ignite in your engine, and will cause gum and gunk to leave solution as solids. That's bad.


In other words, Joel, its just bad to try to save your gas....I am sure one of the local marina's will pump out your gas - mine did for me and they said they do it all the time because the problem is common.....and that is the answer to question you asked.

[boscoe99]

On the other hand, here is what Exxon Mobil has to say about the shelf life of gasoline:

Does gasoline have an expiration date and how long can it be stored?

In general, gasoline should be used within a month of purchase. When the engine will not be used for an extended period of time, it’s best to drain the fuel tank and then run the engine until it stalls. If you choose to store gasoline and follow proper storage guidelines, the gasoline can be expected to remain of good quality for at least six months.

Gasoline Safety and Fuel Storage Tips | Exxon and Mobil

[KlinkSanford]

I bought a boat with 30 gallons of old fuel maybe one year old, maybe more. I didn't like the smell, so I drained it into 5 gallons containers and gave them away on Craigslist for farm or land clearing use (bonfire, parts cleaner whatever). The ad showed a red 5 gallon tank with FREE GAS written over the tank. Next day a farmer came and emptied the tanks into his tanks and was tickled pink.

I then took the boat to the gas station and filled it with 30 gallons of non-ethanol 89. Then I ran the stuff (1 gal.) through the lines and out into a small tank and kept that for my bonfire. Then I ran the clean fuel all the way past the fuel water separator and to the engine and out the carb fuel rain, again discarding the fuel to bonfire material.

All of that, and then I tested the engine on the water, it idled great, but would not rev-up. Had to clean the carbs. That is where I am now, I cleaned the carbs and am waiting for the parts kits to come in maybe tomorrow.

Old fuel, bad news!