Cleaning a plastic fuel tank?

I now know what bad gas smells like. Ew. The old gas is on the brush pile awaiting ignition, I've wiped out everything I can reach through the fuel pump hole. What now? Put in a half gallon of fresh gas, swish and drain? Do it twice?

Shouldn't really be much to do but start running it and change the fuel filter after a few tanks.

Watching with interest. My son's dirt bike has a plastic tank that was filled with putrid fuel when we got it. I drained it, and swished it out with fresh gas, redrained it and left it empty for weeks.

Now whatever gas I put in seems to go sour after sitting only a week or so.

I'm wondering if I need to wash it out with acetone or naphtha?

once drained and the old gas and cleaner evaporated dry, there shouldn't be anything left that would cause issues. it isn't like a rusty steel tank that would clog a filter. whatever residue left in the tanks would be the same in a plastic tank as it would be in it a new steel tank.

Unless it was coated. I had a plastic motorcycle tank that had a caswell coating to help with swelling from ethanol that peeled off and caused some issues.

It had this inside. The brown stuff isn't chunks, it's a second phase of liquid. It sticks to skin like tar. It's unpleasant.

mazdeuce wrote: The brown stuff isn't chunks, it's a second phase of liquid. It sticks to skin like tar. It's unpleasant.

Shoot...that's just liquid dinosaur goodness.

It's stuck under my fingernails and smells funny.

I've successfully used regular dish soap and hot water in plastic dirt bike gas tanks to get the gross stuff out, but those are small enough to be easy to shake vigorously.

I had to clean a tank out once (It was metal though) and I poured paint thinner in, let it sit, shook it up and then drained. Repeatedly. Took a few years off my life expectancy but it got it clean

I've used MEK on steel tanks, but wouldn't on plastic.

Ok, gas, sloshing, wipe anything that shows up. Repeat until clean. Change the filter after a bit. Many thanks.

Hot water and soap, preferably from a high pressure washer. Then either a vacuum cleaner on blow, or a helping of methyl hydrate to dry it.

Toss a chunk of chain or several large nuts in there with the gas when you slosh some around. Then it will be clean when you dump it out for sure.

It was once gasoline, fresh gasoline should dissolve it.