Old Gas versus New

[Doogie]

OK, so please forgive me, but I have an old Gas question, and you guys are the first ones I thought of to ask...

I have an old Boat (1957) with a standard Round tank in it. Last time I used it was June of Last year (so just over a year ago). The boat was winterized and fuel additive (Sta-Bil) added.

When I took the boat out today, I measured the tank (about 4 inches of fuel). I stopped and added 10 gallons, (for a total of about 12 inches give or take).

Went boating, and not longer after starting, the boat would periodically "Cough and spit" a little bit. Not stall, just cough and spit.. At first I was thinking "bad fuel", it will work itself out once the fuel bowl and pump and line (5 feet) are cleared.

an hour later it's still coughing and spitting!

So I idle around, periodically running her wide open (to empty the bilge) and then futz around for another hour.

Suddenly, I could hear a change in the tune of the engine (a change to the better) and she ran GREAT after that, like I'm used to hearing her.

So, I was pretty sure that bouncing around the lake all day would have 'mixed' the gas in the tank pretty well. But the above experience almost made me believe that the bad gas stayed on the bottom of the tank, and once it was finally depleted, the good gas took hold.

That sound right? doesn't seem right I don't think...

Again, my apologies if I'm posting incorrectly here. I just thought that almost all of us have dealt with bad gas once or twice... and we're all gear heads...so I value your opinions..

Thanks,

Doogie

[David T]

Old gas with stabilizer added is not very good. Even the mixing and shaking with some new gas may not have fully mixed it together. When you finally used up all of the old stuff the motor started running better. I would try to use up as much of what's in the tank as possible and fill with fresh. Today's gas is considered stale after 6 months. Next time you store it remove as much fuel as you can and store it empty.

[kings1527]

The best way to store anything long term would be with a full tank of gas coupled with StaBil. When you have space in the tank, it will allow for condensation and fuel separation to occur and that's when you get water. Even when you add StaBil, which is a great product. Adding fuel stabilizer AFTER the fact doesn't get rid of the bad stuff that's already happened with the fuel. It has to be added beforehand. It's also never good to take a gas can and use every single bit of gas in it. Leave a little bit behind, banking on the fact that it might have water in it from being stored.

The engine was probably sputtering through the condensation but had enough fresh gas eventually to where it was running good. All should be good but next time fill the tank completely and add StaBil and I'll bet you'd have zero issues.

[kings1527]

And yes, that's true, completely empty is probably the best option for storage for 6-12 months but it's a ton easier just to add StaBil first and fill it up completely.

[DMCMW Dave]

Water in the tank? It stays on the bottom until gone. . .

[Doogie]

Thanks Gang. The first hour of running I was afraid to venture too far from our dock for fear of a breakdown. My Mind tends to wander when I'm in these situations... "I bet those plugs are bad..", "I wonder if the points are corroded..", "those a-holes at the boat shop screwed this engine up (My favorite :-)"....

The boat is a wooden boat which needs to be swelled for 3 days before launching, else it will sink to the bottom of the lake! (Think Whiskey Barrel). They have an "evacuation" tube which will remove water that seeps in, but it only works under full speed. I was toying with getting it back onto the trailer (bad) and just "running through the fuel" until she started running good.

I pulled about 5 gallons of varnish from my Delorean when I first got it. Very akin to bad fuel. I think I might take your advice and fill the tank before I store it at Ken K's this winter.

Dave, your comment about water v fuel is dead on.

Thanks gang! I appreciate it!

Doogie

[Bitsyncmaster]

What I have noticed with my yard power tools that don't get used much is some of the carburetors get plugged up a little with old gas sitting in there a long time. Most of them will clear up if used for a long time after I find they only run with a lot of choke to keep them running. My pressure washer is good example of the problem since when it gets used, it runs for many hours. I have a chain saw that never seems to have that problem though.

So I think it all depends on the carburetor design.

The new yard tools have these carburetors without mixture adjustments. If I see no mixture adjustment on a new yard tool I want to buy, I look for another one which has that adjustment.

[Soundkillr]

What I have noticed with my yard power tools that don't get used much is some of the carburetors get plugged up a little with old gas sitting in there a long time. Most of them will clear up if used for a long time after I find they only run with a lot of choke to keep them running. My pressure washer is good example of the problem since when it gets used, it runs for many hours. I have a chain saw that never seems to have that problem though.

So I think it all depends on the carburetor design.

The new yard tools have these carburetors without mixture adjustments. If I see no mixture adjustment on a new yard tool I want to buy, I look for another one which has that adjustment.

I always remove excess fuel from all my yard equipment. For my weed eaters I just dump the fuel out and back into the can, then run them till the carb is dry. For my lawn mower, I close the fuel cock and run it till dry. For my pressure washer, I pump the fuel out and run it dry. This is for all off season, or storing and I've never had an issue.
That fuel will mess up a carburetor REAL quick. I learned my lesson, on my celica, I had rebuilt everything, and even new weber carbs. I forgot I didn't run it dry, and let it sit for 6 months. I had to drive it for a week to clear it up. Now, pull the fuel pump fuse, and run it dry. It could sit forever, and all I do is prime the pump and it fires right up.
I have rebuilt several neighbors weed eaters, and blowers because of this fuel. Now, when they store them, they run them dry. None of them have an issue anymore.

[David T]

I always remove excess fuel from all my yard equipment. For my weed eaters I just dump the fuel out and back into the can, then run them till the carb is dry. For my lawn mower, I close the fuel cock and run it till dry. For my pressure washer, I pump the fuel out and run it dry. This is for all off season, or storing and I've never had an issue.
That fuel will mess up a carburetor REAL quick. I learned my lesson, on my celica, I had rebuilt everything, and even new weber carbs. I forgot I didn't run it dry, and let it sit for 6 months. I had to drive it for a week to clear it up. Now, pull the fuel pump fuse, and run it dry. It could sit forever, and all I do is prime the pump and it fires right up.
I have rebuilt several neighbors weed eaters, and blowers because of this fuel. Now, when they store them, they run them dry. None of them have an issue anymore.

It is not recommended to run 2 cycle equipment dry. The fuel is also the lubrication. Just empty out as much fuel as you can.

[Soundkillr]

On 2 cycle yes, all my equipment is 4 stroke, including weed eaters. I hate oil mix...

[DMCMW Dave]

It is not recommended to run 2 cycle equipment dry. The fuel is also the lubrication. Just empty out as much fuel as you can.

Huh? When the fuel runs out the engine is gonna stop. Right now. I don't see the oil problem.

[Soundkillr]

Huh? When the fuel runs out the engine is gonna stop. Right now. I don't see the oil problem.

This was my thinking as well. They are designed to be able to run out of gas....

[David T]

This was my thinking as well. They are designed to be able to run out of gas....

The problem is the crankcase gets dry while there is still fuel to keep the motor running. While you can probably get away with running out of gas a few times, if you regularly do it you will eventually wear things out. A lawn mower shop warned me about running a 2 stroke dry because he has seen the results.