Did I ruin my motor with old gas?

[bagpiper13783]

1989 Lowe pontoon with 1989 Evinrude 40hp Tracker with VRO

Just got the boat recently and there was already some gas in the tank (older style 6-gallon metal oval gas can). Has started and run beautifully since we got it. Last weekend, was planning a long day on the lake, so I stupidly added 2-3 gallons of 87 octane gas from the gas container in my shed into the tank. Gas has been stored in 5-gallon plastic fuel container for at least 2 years, possibly 3 or 4. Lake is midstate NY, so hot humid summers and bitterly cold winters.

The boat ran ok that evening and started/idled fine the next day, but as we left our dock, it began to surge when I wasn’t giving it gas, then it would stall when I tried to accelerate. She started again and made it a few feet, then stalled. It would start and run briefly, then die. We floated for a while, then tried again…same thing. Would start then die. A friend towed us home.

I’ve since read about Ethanol and phase separation, and it certainly seems like the bad gas was the cause of my issues, and can mess up a motor. Luckily, I only ran a little through, but maybe that’s enough to cause permanent damage? I have another empty tank that I can fill with clean gas and try again this weekend. I’ll empty the fuel line as well before I use the fresh gas.

Questions:

1. Assuming the old gas was the issue, is there anything I need to do to the motor before running new gas through?
2. I bought some Sta-Bil marine fuel treatment. Does adding that to the gas interfere with the automatic VRO oil mixing at all?
3. What’s the recommended method of getting rid of the old gas?
4. Lastly, I was working on the wiring for the navigation lights before taking the boat out. All the accessories are on a separate fuse box, and the motor started fine at first, but could my tinkering with the wiring have affected the motor’s ability to stay running?

Thanks in advance.

 

[Scott Danforth]

Welcome aboard

gas normally lasts only 12 months from the time its refined.

1 - clean the fuel system (tank, lines and carb)
2 - not needed with fresh gas
3 - bonfire
4 - doubtful

 

[racerone]

Did you confirm that VRO is working properly ?----I often say mix the first tank with 50:1 and monitor oil level in the oil tank !---Extra oil won't damage the motor !----Have you installed a new water pump impeller ?

 

[tpenfield]

:welcome: to iBoats . . .

You are going to have to work harder than that to ruin your engine.

Old gas is not the best thing, so a fuel system cleaning is in order. Usually you can get away with adding a few gallons of old gas to a larger tank. Seeing it was only a 6 gallon tank, the old fuel prevailed.

Old gas is why lawnmowers were invented, so that's the best place it should go.

 

[emoney]

Agreed with everyone else. Nothing permanent, so all is well. Use that old gas for your lawn mower. It won't mind. Although I've known guys who would run it in their truck. Make sure you screwed that fuel cap on the tank down well too. Check the primer bulb after it's running and confirm it's still firm.

 

[oldboat1]

I have a couple of old stumps in my back yard that I'm trying to help die back.

Recommended fix is to dismantle and clean the carb. Try running in a barrel with fresh fuel first (may be enough).

 

[iggyw1]

I've done the same thing as you did in the past, and the motor ran terrible! I added fresh gas the next day into the gas tank and also, I gave the tank a good dose of Sea Foam to clean things up. Ran great after that as the old gas was burned thru the motor with the fresh gas and Sea Foam. I use Sea Foam all of the time at 1/2 oz. per gallon of gas. When old gas was put in, I used 2 oz. per gallon, and it worked wonders.

 

[kbait]

Hook fuel line to fresh fuel tank, block open the little BB In connector that you normally plug to motor and set in waste container, pump primer to purge old fuel from line. Now connect fuel line to motor, open top carb bowl drain, squeeze primer and collect 1/2 cup of old fuel in cup or rag, replace bowl drain plug and repeat process on lower carb. You should now have very little bad fuel in system. Fire it up and cross fingers. It will likely run fine after a minute or so, and you can fish the afternoon away instead of pulling carbs. Good luck!

 

[bagpiper13783]

Thank you all for the great advice. I'll be back at the lake this weekend and will report back.

i appreciate it!!

 

[bagpiper13783]

Just closing the loop...fresh gas did the trick. Took a little while to get all the old crap out of the system, but we just got back from a long lake ride. She's back!

thank you for the advice! Happy boating.

scott