Should I be worried about my 3 month old fuel?

[Corey_lax]

Hi,

My OB is a 1981 Johnson 115. I haven't used my boat for exactly 3 months, and I have about a tank and a half worth of mixed fuel leftover. Normally I fill up with Chevron 94 octane, but this was Osoyoos marina gas. I didn't put stabilizer in as I thought I would have used it more. I'll be heading out tomorrow, so what would you do if you were in my shoes? I've read that mix gas goes stale a lot quicker than straight gas, and I'm worried about the quality of the Osoyoos marked gas to begin with.

1. Dump both tanks and start fresh and add stabilizer
2. Top up the half full tank with fresh, and dump the full tank that is probably crap.
3. Shake up the existing fuel and go fishing with the old gas

 

[scott craven]

Marine gas is usually mid grade and a good chance it's ethanol free.
I would dump a 1/2 can of seafoam in the tanks and run it up.

 

[KV1]

Non issue. Weedwacker has been running on one tank for two years. No issues.

 

[gungadin]

I have used 6 month old mixed fuel in the past and while it was ok and ran fine, the difference when using new fuel was noticeable. it was like I gained 10-15 hp. As I have three tanks, I just divide the old fuel as equally as I can between them now. Getting rid of the old fuel in an environmently friendly way is not an option in my town unfortunately. I have thought about putting a litre or two in my vehicles fuel tanks at each fuel up, but I need to a little more research on the how the oil would affect sensors and cats. So far though it seems it may be an option.

 

[Bait&Sea]

Three months isn't an exceptionally long time, that being said if I felt like gambling I would probably split the tanks evenly and top each up with fresh mixed gas. I would be listening very closely to the power head for any signs or sounds of detonation (pinging). The other unknown is how much moisture the fuel absorbed over the three months if it does indeed have ethanol in it?
A 1981 2 stroke is bound to have some carbon buildup somewhere, $60 worth of fuel could turn out to be the worst wager you ever put down...

 

[Canso]

if your worried, put it in the wife's car and buy fresh for the boat.

But I would shake it up and go fishing. Some of the 2 stroke oils have stabilizer in them, I would only be worried about oil separating.

 

[Corey_lax]

No issues with the fuel on Saturday morning. We burnt through a tank and half. Weather was snotty in Howe Sound so we ended heading up Indian Arm and getting skunked for prawns.

 

[happy hooker]

Osoyoos marina fuel is the best in the Okanagan, wtf you talkin about Corey? Oh ya and next time tie a rope around my brothers waist so he doesn't almost get deep-sixed.....

 

[Breaking_Shimanos]

Regular checks of fuel filter and water filter or VST bleeder valve.

 

[Corey_lax]

Osoyoos marina fuel is the best in the Okanagan, wtf you talkin about Corey? Oh ya and next time tie a rope around my brothers waist so he doesn't almost get deep-sixed.....

Hahaha I don't like it when water is coming over the bow and almost over the windshield on every wave. It probably calmed down as soon as we left. Owell. I'll put a tag line on him next time.

 

[Kildonan]

I've burned year old 50:1 mix in my old 9.9 two stroke evinrude and it burns it like a champ.

 

[JAC]

Older 2stroke carbs have larger jets and a lot less trouble then new four stroke carbs. I would think you'd good to go but in the future I would you stabilizer I have found that out the hard way.

 

[Corey_lax]

Yeah definitely bigger tolerances on the old girl. I'm not worried about it now. I have stabilizer in the one tank that has fuel now.

It was loading up at idle and would stall out some times but I've been meaning to clean the carbs for the past year anyways.

 

[sly_karma]

Carb clean on those crossflow V4s is easy, I do it on my 140 every 2-3 years. Premix means same 50:1 oil all the time, things get gunked up over time and rough idle is the first thing to show. The carb kits are under $40 per carb and very easy to do. Just need some good carb cleaner for an overnight soak.

 

[gungadin]

Fuel stabilizer is great stuff as long as the gas it is in doesn't completly evapoate. It will leave a sticky substance on the inside of whatever it was in, tank, lines, carburetors. Drain carbs before adding fuel stabilizer.