old fuel and older fuel

[gonelong]

A quick question about fuel. When is it "too old"?

Old Fuel: I have about 4 gallons of 87 octane that was purchased this spring and treated liberally with SeaFoam, It has been sitting the boat in a plastic fuel cotainer ever since. Should I drain this and do something else with it? My lawn mower is oil injected, so I don't think I have much use for it. Would it be too risky to add a bit more SeaFoam to it and burn it up early next season?

Older Fuel: I have a tank that came with the boat. Fuel is probably 5 years old. I'll call my county to see if they have disposal somewhere. Can the tank be used if it is given a good cleaning, or is it a gonner?

Thanks,

GL

 

[Silvertip]

Re: old fuel and older fuel

Question: What two stroke lawn mower is oil injected???? If that's true, then mix the two containers of fuel and run it in the mower. If you have any other gas engines use it in those. If one of your friends (or you) have an older car or truck, use pour it in that.

 

[gonelong]

Re: old fuel and older fuel

Question: What two stroke lawn mower is oil injected????

Not mine, ha ha. Not sure why Oil-Injected came to mind. It has a seperate oil resivoir, resivour, resi ..., holding tank. The Riding mower is only a year old, that gas is going nowhere near it.

If that's true, then mix the two containers of fuel and run it in the mower. If you have any other gas engines use it in those. If one of your friends (or you) have an older car or truck, use pour it in that.

A 50/1 Mix in the car? Hmm ...

GL

 

[Merc25XD]

Re: old fuel and older fuel

I am putting some of this late years mixed fuel (50-1) in my cars...works just fine. Just make sure that you have at least 1/2 tank in your car before you dump some in. I put about 1/2 gallon in my cars when they have about 1/2 tank or more. Why waste the fuel....at $3+ per gallon. It works for me....

 

[Laddies]

Re: old fuel and older fuel

For many years before the advant of leaded gas, almost ever major gas company sold what they called valve top lube (oil) to mix in the fuel to lube the valves--Shows how old I am-Bob

 

[Silvertip]

Re: old fuel and older fuel

Marvel Mystery oil is one of those upper cylinder lubs that appeared when I wrenched in my Dad's Chevy dealership -- some 56 years ago. Marvel Mystery Oil made a resevoir that was mounted under the hood and a tube was run to the intake manifold. A needle valve adjusted the amount of oil sucked into the engine. The only issue today with oil in the fuel is it can mess with oxygen sensors. In this case (old and older fuel) I don't recall it being pre-mixed. If it is, add some fresh to it and use it in the car/truck.

 

[Lone Duck]

Re: old fuel and older fuel

remember that mix oil is made to lube crank & rod bearings then it burns off in the upper chamber. When putting it in an engine with valves it will burn off in the compression chamber creating more heat and residue . Over time it will cook your valve seals and distorte your valve seats. causeing loss of compression or worse. I have proved this fact time and time again, the guys became beleivers after a year or so. At the very least it means a valve job . You will get away with it for awhile, but in the end it will get your wallet.

 

[SeaKaye12]

Re: old fuel and older fuel

I've always put the few gallons of 50:1 I have left over into my Camry. Never had an issue. Of course; it's only a few gallons being poured into a tank with 10 or more gallons in there already. That would be a miniscule amount of oil in that much gas. Hard to imagine it doing any damage. Plus; I only do it once a year; if that.

Chuck

 

[Silvertip]

Re: old fuel and older fuel

Lone Duck -- you proved it how? We would really like know. For example, how much did combustion temps rise and how did you measure it? How did you measure valve seat distortion? A 50:1 mix (1 pint in 6 gallons of fuel) when mixed with 10 or more gallons of unmixed fuel creates about a 125 -150:1 mix. If one is talking about 3 gallons or less that number can go as high as 300:1. I really don't believe that will cause all of the problems you contend so prove us wrong! I do agree that a too rich mixture might foul an oxygen sensor, however, two-stroke oils are designed to burn so the mixture would have to be really rich to cause that problem.

 

[Vlad D Impeller]

Re: old fuel and older fuel

The modern vehicle engines are quite a bit more refined than those of yester-years, i don't believe that it would add any benefit to your vehicle by using premix 2 stroke gas.

 

[Laddies]

Re: old fuel and older fuel

Silvertip, I saw the post by the duck and it's not worth the effort to argue about a little like arguing about oil or I could argue for days about my to pet peeves, stabil and various decarbing products. We had bad luck with the latter of the two, many years ago and haven't used it since in winterizing and in 50 years of outboard repair only had to decarb one engine if you use quality oil you won't build carbon in a engine, we run our racing engines as high as 12 1/2 to 1 and never had carbon in one at tear down. Don't want to argue about any of it, just two cents worth from a old guy--Bob

 

[Lone Duck]

Re: old fuel and older fuel

Silvertip;
I have no scientific prove. Just experience over the years with engines.
(1st) Different mix oils burn off at different temps. And have different lube qualities. That is why you don't (should not) use a mix oil that claims to be good for chainsaws,lawn mowers, outboards,etc:
(2nd) Oil detonates slower than gas creating longer heat time in combustion chamber. causing oil build up around valves because of the time between burn off and valve opening and closing in a 4 stroke.
(3rd) 2 stroke engines are timed by the piston in relation to the intake and exhaust ports built into the cyl. No matter how perfect you mix your fuel,if you take off your muffler after 50 to 100 hrs. of use, you will find hard black & oily deposits around the exhaust port & muffler entry. I have seen cases where it has flaked off and scratched piston rings. this stuff also retains the heat longer. It is almost like a lava rock in your barbecue .
(4th) In time this will affect a 4 stroke. I 1st fund it in my neighbours car engine back in the 50's and a few others over the years.
After a maintinence check up on customers engines, I ask them what fuel they are using , they say regular and sometimes left over mixed gas. I say don't do that, they say why? I explain. They say B S . I say Ok. Depending on how often they do it,they next year or the next. I redo thier valves and they become believers.
I am telling you this because I would like to see you spend your hard earned money having fun with your toys, not fixing your tow car.
Now that I have built a boat I just wish I had gone into outboards. Oh well just another learning curve for me.

 

[Lone Duck]

Re: old fuel and older fuel

Laddies;
Nope ! Not going to argue . Just warning what I believe. Of course I could be wrong. I was wrong once before , But I just can't remember when.

 

[nathanglasgow]

Re: old fuel and older fuel

I have always put any left over two stroke in the fuel tank of my car.Been doing it for years now.However i run a BMW 318 diesel which i doubt even exists in the USA.Nathan