Bad Fuel - Help

[Bereforest]

I have just purchased a 96 Bayliner with a 4.3 LX V6 Mercruiser. The boat had half a tank of fuel in which I topped up with another half tank of fresh fuel. After 40 minutes running we developed a bad misfire. On advice to check the fuel I have taken a sample which unfortunately smells heavily of varnish. I suspect the old fuel had sat for some time. I'm a bit reluctant to dump 40 odd gallons of fuel, but concious of not doing any further or long term damage to my engine. Are there any solutions that could allow me to burn off the old fuel without any lasting damage?

Also do I need to check / replace all fuel lines that may have developed a residue from now having pumped through this bad fuel?

Thanks.

 

[Gary H NC]

Re: Bad Fuel - Help

Not much choice...drain it and burn it in the lawn mower..The mower won't care.
Change the fuel filters and fill up with fresh fuel.Add a couple cans of Seafoam...

 

[gshldon]

Re: Bad Fuel - Help

I agree drain it and add seafoam, i had the same problem,, but i just added the seafoam and it cleaned everything really well, except that after a few runs with the seafoam in the gas, i had a float stick open from some gunk and it allowed gas to poor into the carb and into the oil, i drained the oil before running it again and never had a problem after that and it runs smooth as silk. I would suggest using premium fuel in it and with the last tank of fuel but some seafoam or other fuel stabilizer in it just before winterizing, that way the fuel will not varnish up over the winter.

 

[180shabah]

Re: Bad Fuel - Help

Do not waste your money on premium - it will not help anything. Regular gas will be just fine.

 

[gshldon]

Re: Bad Fuel - Help

i beg to differ with you on the premium fuel. It does not break down like regular unleaded fuel does, it is recommended in all small engines that are not used that often so they do not varnish up from sitting, i have used it in all my engines and have never had any problems with varnish at all, i had premium sitting in my snowblower for 2 years and there was no varnish smell in the gas and it started right up and ran like brand new, i have worked on many engines that have sat just over the winter with regular gas in it and the cards were all varnished and need to be pulled apart and cleaned in order to run.

This is just based on my experience and i know i will run nothing but premium in any of my engines that dont get used all that often. the few extra cents per gallon is worth it to me knowing i will not have a fuel related problem

 

[Polar_Bus]

Re: Bad Fuel - Help

I have just purchased a 96 Bayliner with a 4.3 LX V6 Mercruiser. The boat had half a tank of fuel in which I topped up with another half tank of fresh fuel. After 40 minutes running we developed a bad misfire. On advice to check the fuel I have taken a sample which unfortunately smells heavily of varnish. I suspect the old fuel had sat for some time. I'm a bit reluctant to dump 40 odd gallons of fuel, but concious of not doing any further or long term damage to my engine. Are there any solutions that could allow me to burn off the old fuel without any lasting damage?

Also do I need to check / replace all fuel lines that may have developed a residue from now having pumped through this bad fuel?

Thanks.

Welcome to the world of EPA friendly E10 fuel. It has a shelf life of about 30 days. Befor you go through all the trouble of draining all the fuel try adding some of this additive:

http://www.starbrite.com/productdet...nd Diesel Additives&ProductSSCat=Startron Gas

Startron in some cases has actually been able to reverse fuel varnishing. Let the stuff sit for about a week in your varnished fuel, and you might get lucky...

 

[NoGin]

Re: Bad Fuel - Help

I bought a boat about 3 months ago that had over 50 gallons of bad fuel sitting in the tanks. The only thing you can do is drain it....

This is what I did:

*Remove the Fuel Sender.
*Using a hand pump (for safety reason) drain all but a few gallons from the tank.
*Take a rigid wire (I used an 8 gauge battery wire) make funky bends in it and insert and shake it around the bottom and sides of the tank. You will hear it.
*Add 2 gallons of 89 octane that you treat with E-Zorb as directed.
*Agitate tank again.
*Drain the rest out until you have a steady stream of clean fuel (do this for about 5 minutes worth of clean stream).
*Now add 4 gallons of fresh 89 octane without treatment and run engines.
*You will have to use a carb cleaner to spray into the carb to get her fired up then continually to clean her out. Spray enough in while running until she is about to stall out, wait, do it again.

>>>>> I drained 50 gallons into a 55 gallon drum I bought from a lady on craigslist for $20.

>>>>>> I will be using the drained fuel to run my cars. I treated the gas and tested it in my sons go-kart. Ran great!

>>>>>> As we all know E10 gas does not allow the water to burn in the fuel rather lets the water drop and sit in the bottom of the tank. In our boat the fuel pickup is down where the water and "gunk" settle. In your drum that you drained you can skim the clean fuel from the top and use so as not to waste it.

Good luck. Any questions please feel free to PM me or email me anytime.

Joe

 

[NoGin]

Re: Bad Fuel - Help

Welcome to the world of EPA friendly E10 fuel. It has a shelf life of about 30 days. Befor you go through all the trouble of draining all the fuel try adding some of this additive:

http://www.starbrite.com/productdet...nd Diesel Additives&ProductSSCat=Startron Gas

Startron in some cases has actually been able to reverse fuel varnishing. Let the stuff sit for about a week in your varnished fuel, and you might get lucky...

I tried the recommended amount of Star Tron prior to draining and it didn't help my situation one I-Oda! And yes, I had it sit in the tank for about 2 weeks.

 

[bruceb58]

Re: Bad Fuel - Help

According to my friend who is a chemical engineer for Chevron, premium fuel and regular fuel have the same breakdown characteristics....sorry to burst any bubbles.

 

[180shabah]

Re: Bad Fuel - Help

premium fuel and regular fuel have the same breakdown characteristics....

...but it will give you an extra 3.2hp per cylinder.

 

[Arabian180]

Re: Bad Fuel - Help

...but it will give you an extra 3.2hp per cylinder.

Yeah, Just like those Holley and STP Hot Rod stickers on the windows give and extra 10Hp each.

 

[kumi]

Re: Bad Fuel - Help

call a local hot rod parts store see if they sell 110 octane race fuel get 10 gallons they come in 5 gallon cans and add it to your fuel this will turn your varnish to a lowgrade gas it will run rough but one day of boating should do it.

 

[180shabah]

Re: Bad Fuel - Help

Just like those Holley and STP Hot Rod stickers on the windows

...but nothing give more hp/$ than CHROME!!!!


Back to the disposal question - It runs now but developed a misfire, most likely you already need a carb rebuild. The inside of the carb was sitting with the same gas that was sitting in the tank and now that sludge is moving around, getting trapped in the small passages. Change your fuel filter, run the tank as close to empty as you can(if the engine is running well enough to do this, may have to baby it, no skiing, WOT etc). Change the filter again, fill the tank(again regular gas fine, higher octane will increase carbon buildup, especially if you idle alot). rebuild the carb(you have a weber so it is fairly simple, and you can save some money getting the parts for an edelbrock performer, instead of the merc kit), replace the anti-siphon valve, go enoy your boat. If your fuel was as bad as it sounds for any lenght of time, you may also be needing a new fuel pump, but I wouldn't replace it until it fails (unless your an ocean boater, or other dangerous water, and a breakdown would be hazzardous, not just inconvenient)

The manuals for both you engine and drive are available for download (FREE)in the adults only section and if you would like the weber carb suppliment, PM me with your email and I will send it to you.

 

[180shabah]

Re: Bad Fuel - Help

Forget to mention - if your engine is not running well enough to burn the gas, you have an electric pump, so just disconnect the line to the carb and attach a hose down through the bilge drain and pump it into anything you'd like - truck, car, gas cans etc...

Easiest way to power the pump, jump out the oil pressure switch and turn the ignition key on. Wiring digram is on page 4E-2 of manual #18.

 

[NoGin]

Re: Bad Fuel - Help

Stay away from the premium fuel. They aren't admitting to it yet but they increased the E10 already to E15 or better in premium (at least we found this at a local station here in NY). I have a buddy with a bored out hot rod pick up truck and the premium nearly wrecked his fuel system not to mention the awesome smell it omits! He now mixes 89 and 110 to get the good performance and fuel delivery he needs to run his joint. He noticed this starting just about a month ago.

 

[capecodder116]

Re: Bad Fuel - Help

Get some 5 gallon jerry jugs drain all the fuel and burn it 50/50 in your car or truck...that's what I did. Then throughly clean your fuel tank, replace your water seperator (filter), carb fuel filter, and put some fresh fuel in it the tank, take the boat out and run it....if it still gives you headaches rebuild the carb....

 

[87 caravelle]

Re: Bad Fuel - Help

how come its "ok" to run bad/varnished fuel in the family car but not in the boat? particularly in i/o motors....thery're the same beast right? im confussed on this one because bad fuel is bad fuel so why fun it through your everyday driver?

 

[JustJason]

Re: Bad Fuel - Help

Instead of dumping all that fuel first. Go and get a small outboard style fuel tank and fill that up with fresh gas and hook it up to your fuel pump to see if your misfire goes away.

 

[Bt Doctur]

Re: Bad Fuel - Help

got it all wrong,
Race fuel is 30 hp/cyl and the stickers add 15 hp /sticker, "Mothers Silicone Polish" gives a extra 20hp