old gas/new gas

[Marty Levenson]

My 20 gallon tank is about 1/3 full of two and a half year old gas. It is working fine still, but I'm wondering about topping up. Am I better off trying to burn up this old gas before it gets too old, or simply adding fresh gas now? I always put in a glug of Marvel Mystery oil.

Thanks!
Marty

[joe_db]

I would be thinking of a way to get rid of that old gas and fill up with new gas. Adding new to old just is not a good idea IMHO. If that gas can be used, burn it something now, it is living on borrowed time at best.

[BadaBing]

Suck it out. Pump it back in to stir up the dregs. Pump it out again. Fill with fresh gas.
Mix the.old.glass with old crankcase oil and take to the local recycling center, (if they will take gas don't add the dirty oil) I have disposed of a good deal of old g a s by exasperation in a shallow.open pan. Dangerous if you can't control the space. Not exactly a green idea.

[sail_flathead_lake]

I'm in the same boat. I put maybe an hour or two tops on the Tartan 27 each year. The tank hasn't been filled in three years. It's still more than half full. What a pain! But I understand that leaving it half full over the winter is a bad plan too. So the recommendation is siphon out 19 gallons at the end of every season and top with fresh? Uggh... worse that the oil change and winterization routine. I will spend more time working on the engine than running it!

[joe_db]

Opposite ends of the spectrum. I use at least 100 gallons a year.
I would see about getting a small fuel tank welded up. For you 5 gallons would be plenty.

I'm in the same boat. I put maybe an hour or two tops on the Tartan 27 each year. The tank hasn't been filled in three years. It's still more than half full. What a pain! But I understand that leaving it half full over the winter is a bad plan too. So the recommendation is siphon out 19 gallons at the end of every season and top with fresh? Uggh... worse that the oil change and winterization routine. I will spend more time working on the engine than running it!

[BadaBing]

It may be possible to just continue using it and adding more gas when needed. But it is also likely that you will eventually developed a clog of Sony and grime in the filter or carb. Normally these troubles show up at the worst possible moment, like while running against the tide in a narrow inlet.

[Mo]

Gas typically starts to deteriorate after 2 months...that's "starts" to deteriorate, doesn't mean it's bad. Lots of people leave gas in machines, small engines etc all winter then fire them up and use them in the spring. Warmer climates, I'm sure it will deteriorate worse than colder. Thing about stabil ... it won't make bad gas good...but it will give gas a longer life for sure. I've started things a full year after last use using stabilizer and they ran fine.

My thoughts on your question Marty: If you have gas in your tank and the engine will run on it just put some stabilizer in it...it will stabilizer it from that point. You could fill it up with new also and stabilize the whole works. Another point to add on this. If you know you only burn a tank or so a year you might as well just get in the habit of stabilizing your gas when you top up. The stabil is relatively inexpensive and could potentially cut down on debris/crud as well.

[hanleyclifford]

My 20 gallon tank is about 1/3 full of two and a half year old gas. It is working fine still, but I'm wondering about topping up. Am I better off trying to burn up this old gas before it gets too old, or simply adding fresh gas now? I always put in a glug of Marvel Mystery oil.

Thanks!
Marty

It will continue to "work fine" until it doesn't. That event will occur when the water/crud level in the tank reaches the pick up tube. This will usually occur when you are pitching and slamming your way back into a jettied inlet with wind and tide opposed. You can continue to add fresh gasoline but that will not affect the growing monster reaching for your pick up tube. The end of bottom drains (coupled with the joy of ethanol) ushered in a new era of fuel tank sanitation difficulty. Drain the tank at the end of the season and find a way to clear the sludge.

[Marty Levenson]

still wondering...

Thank you for the replies.

To clarify, I don't think crud and water are issues in my case. I cleaned the tank 2.5 years ago, and I have always had in total three filters. First a truck filter, then the standard raycor filter, then the fine polishing filter between gas pump and carb. Ethanol is not an issue either, as I use the "farm gas" (available on our island as long as it does not go into a licensed vehicle). Also, I do routinely add stabilizer each fall.

I'd like to avoid pumping out the remaining gas unless there is a good reason to. PIA, plus I have to pay for disposal at the boatyard.

So, to narrow the question, wondering if after 2.5 years the gas actually breaks down or loses octane or what? Is there a way to measure that with a sample rather than guessing? A separate question from "might it be full of tank debris and water."

Thanks again!

[Mo]

Thank you for the replies.

To clarify, I don't think crud and water are issues in my case. I cleaned the tank 2.5 years ago, and I have always had in total three filters. First a truck filter, then the standard raycor filter, then the fine polishing filter between gas pump and carb. Ethanol is not an issue either, as I use the "farm gas" (available on our island as long as it does not go into a licensed vehicle). Also, I do routinely add stabilizer each fall.

I'd like to avoid pumping out the remaining gas unless there is a good reason to. PIA, plus I have to pay for disposal at the boatyard.

So, to narrow the question, wondering if after 2.5 years the gas actually breaks down or loses octane or what? Is there a way to measure that with a sample rather than guessing? A separate question from "might it be full of tank debris and water."

Thanks again!

2.5 year old gas wouldn't even run in a vehicle. If it's running at all it must have been treated with stabile. I've seen 2 year old treated gas run in an engine, although was not in a position to determine how well it burned. In a matter of speaking, all we did was fire up a boat that was put away 2 years prior and the gas was treated and run through the carb prior to shutting it down. There were a couple of other issues that had us looking in other directions, starter had seized etc...but once we got it turning over it fired up.
PS: In some remote locations gas is treated with stabil...in Canadian Arctic we'd have 45 gallon drums of gas and they were treated because we really never knew what the consumption would be....most engines, trucks, gen sets, heavy equipment were all diesel. Small things like ice augers, chainsaws, small honda generators all took gas so we always had about 20-30 45 gallon drums laying around.

[marthur]

This may be fuel heresy, but I wouldn't worry at all about 2 year old gas in the A-4. I would try to burn it up before refueling, but I would not sweat it.

My experience is the A-4 will run on any gas that is clean and free of water. I routinely use the old gas from outboard tanks, etc in my motor and have never had a problem. In fact, I have seen an A-4 start and run with gas that was so old it didn't even smell like gasoline. The need for fresh gasoline is much greater in modern engines which have very different design features that the trusty old A-4.

[Dave Neptune]

Mike, I have used even older fuel than that in mine with no problems. I will state that the fuel was "dry" as far as water is concerned.

I do see a bit more green on the floats of the carbs I have done over the last few years but no issues as far as clogging and or performance.

Dave Neptune

[sail_flathead_lake]

My experience, quite limited, supports the idea that dry old gas is fine in an A4. I bought a Tartan 27 last spring, and the PO said she hadn't used it more than a couple of times over the past two or three years. She said that she had not changed the gas either. I worried about whether or not to drain it, and even got a recommendation in favor of draining it from this forum.

I decided that the hassle of siphoning and disposing of 20 gallons of old gas was too much and took the risk of having to clean the carb instead. I'm on an inland lake (Mendota, WI) so there are no tiny inlets to run up against the tide where a poorly timed loss of a motor would be devastating. I ran all last year with no issues. I plan to roll the dice again this year, for the same reason as last year. I'll keep going until she runs dry or clogs up, at which point I will report back to the group.

[JOHN COOKSON]

Members have reported that using gas a year or more old works fine.
This does not tell you what, if anything, is happening inside YOUR tank.
Take the fuel line off at the carb and pump some fuel into a clear glass jar then hold the jar up to the sunlight. This should give you some information to help with your decision to pump the fuel or use it in the engine.
This having been said it is possible to have KRAP settled on the bottom of the tank that gets stirred up when the boat moves or when the boat heels while sailing that you wouldn't see in the jar of fuel.

TRUE GRIT

[BadaBing]

Having lived through a battle with bad gas and its dregs I lean towards replacing the old.gas BUT I sail bays and ocean. Outside, on the ocean, a problems of bad gas and a clogged carb, when they occurs, can add a gray hair or two. Actually an engine shut down at th e wrong time, like while transiting an inlet like Barnegate or Ocean City Md, for that matter any inlet that I know of on the East Coast can be life threttening.

For me reliability is at the top of my list. In addition to the very real possibility of a grounding or being smashed on a rock jetty we also need, and this can be huge, to be able to stay out of the way of big ships. The guys who sail the Chesapeake know this very well.

But even for lake sailors consider the possibility of your engine dying while your trying to get back to the marina and a storm is on the way in. Or even more common as your under lower in the marina itself, possibly with the wind trying to push you into all those anchors hanging off the front of docked boats. How about at that critical moment, when almost completely in your slip, when you need reverse to stop you r boat from smashing.into a fuel dock or another boat at a fuel dock.

Every skipper needs to set his or her own guard rails regarding reliability and safety. For me, a clean fuel system and fresh fuel is very important as a matter of safety, for my crew and boat as well as for other boats around me.

The whole reason around my eyelashes idle jet, in another thread, is a direct result.of my desire for as much reliablity as I can control. BUT that is just my .02