How old is "old" gas?

[old motor]

At what age should you consider mixed gas too old to use in a 2-stroke outboard?<br /><br />Secondly, can old gas prevent an outboard from starting?<br /><br />Motor in question is a 1987 9.9 Evinrude, model CE10RCUE, serial C7212517. It only gets used a dozen times or so each summer, up at our summer cabin. Had a tune-up about 5 years ago, and compression was 120 and 124. It hasn't been used in about a year, but started easily and ran great before it was stored and winterized with fogging oil at that time. Gas is the same age. Now it gives me the silent treatment when I pull the cord!<br /><br />Thanks in advance.

 

[bayliner1972]

Re: How old is "old" gas?

Yes...old gas can be a problem. Full it upo with clean gas and clean your carbs. It should run nice then once again

 

[NJHARLEYMAN]

Re: How old is "old" gas?

Gas is considered old at 4 months but I say more like 3 months.

 

[jfm1]

Re: How old is "old" gas?

did you change the plugs ? my gas is over a year old lol I just add fresh gas when I need to

 

[Joe Reeves]

Re: How old is "old" gas?

It's true that old gas can be termed just that at three or four months, but that does not qualify the gas as being non usable. Many boats are stored for a period of approximately eight months in the northern states, and with built in tanks that contain a hundred gallons or more.<br /><br />The rule of thumb that I and many others use is the odor of the gasoline. When it goes bad, it develops a odor that is referred to as "Stale Gas" and it is unmistakeable even to one who gets a whiff of it for the first time.<br /><br />This odor would (a slight exaggeration) make a drunken skunk head for the hills. Any fuel that develops this odor should be discarded regardless of quanity. Otherwise, I would recommend simply topping the fuel off with new fuel and let it go at that.

 

[old motor]

Re: How old is "old" gas?

Kevin: By "clean your carbs", do you mean taking them apart and cleaning all the parts, or can I just spray some sort of cleaning stuff into the opening?<br /><br />Jim: Yes, I changed the plugs.<br /><br />Joe: I didn't sniff the gas, and the gas is up at the cabin, and I'm at home now. Can you tell me if it's gone bad, just based on its age of one year plus?<br /><br />Thanks for all the help so far, people!

 

[jfm1]

Re: How old is "old" gas?

theres a good chance that your fuel is bad if it sat that long if you did'nt put fuel stabil in and top off the tank with fresh fuel before storing also you should do a carb clean take them apart and soak in cleaner then use compressed air to blow out all passages also if you haven't changed your impeller in a while this would be a good time to do it good luck

 

[DHPMARINE]

Re: How old is "old" gas?

Old gas can be a problem.Lots of fuel stabilizers say 'keeps gas fresh for up to one year'.<br />The problem I find is 1 year old gas runs fine if it's in the tank,but if it sits for a year in the small passages of the carb,that's where it clogs.<br />That's why we use stabilizer,when we winterize outboards.<br /><br />DHP

 

[fireman57]

Re: How old is "old" gas?

If you get a whiff of a varnish smell, it's definitely bad.

 

[marvxyz]

Re: How old is "old" gas?

You should judge the gas by the smell. Old gas does not smell like fresh gas.

 

[bollard]

Re: How old is "old" gas?

IMHO, old gas is subject to interpretation. What I have found is that premixed gas at 50:1 will go stale much quicker.<br /><br />I think that the oil makes the mix behave somewhat like diesel fuel and you then wind up with the evil bacteria chomping away and leaving a nasty byproduct.<br /><br />I have never tried a diesel antibacterial additive, but it may not be a bad idea to use a shot along with the regular (OMC 2+4) fuel stabilizer.