Thanks for the question, Richard.

Yes, you can clean that out using a mixture of Sea Foam and fresh fuel. Sea Foam will help reliquefy the fuel gum/varnish/sludge and clean up the tank.

Here’s what I’d do:

• Mix Sea Foam Motor Treatment with fresh fuel at about a 50/50 ratio
• Pour the mixture into the tank and make sure it’s filled above the contamination line
• Let it sit for 24-48 hours
• Periodically move or slosh the tank to keep the mixture working

If you can, leave the tank in a warm area or direct sunlight. Sea Foam works better with heat and will clean faster.

Once you’re done, dispose of the Sea Foam/fuel mixture.

Hi Kevin,

Good question. Yes, you can use Sea Foam Motor Treatment in your vehicle. With that size tank, 2 cans in a low tank of fuel would do a good job cleaning. I like to wait until the tank is low (1/4 -1/8 tank), add both cans, and then drive for at least 10-20 miles before refueling. It’s safe to add a high concentration like that and it works very well for cleaning fuel residues and deposits. Add it to fuel like this every 3,000 miles or once a year.

You could also try High Mileage Motor Treatment. It’s made specifically for stubborn residues and deposits in higher-mileage vehicles. It’s a great cleaner!

Hi Angela,

Good question! While your lawn mower is probably just fine since it was just one winter, you can add a cleaning dose of Sea Foam to get it ready for spring. When a mower sits with fuel in it, the biggest issue is fuel gum and varnish forming in the carburetor. Sea Foam will clean it up and help make sure it runs well all summer.

Here’s what I’d do before you start using it this spring:

• If possible, drain the old fuel (or run it till almost empty)
• Add a cleaning dosage of Sea Foam to fresh gas (up to a 1:2 ratio of Sea Foam to gas. A 16 oz can of Sea Foam in ½-1 gallon of fuel would be convenient and a good starting point).
• Start the mower and let it run for a few minutes. That will draw the Sea Foam into the fuel system. As you run it this spring, the Sea Foam will continue to clean up any gum and varnish that formed while it was sitting, and prevent any more from forming.

For the rest of the season, keep using 1–2 ounces per gallon to help prevent any fuel-related issues. If you add it to every tank of gas it’ll go a long ways towards preventing problems.

Thanks for the question!

If the tank is already full, I’d add 1–2 ounces of Sea Foam per gallon of fuel.

That said, the best cleaning results come from using a higher concentration. Here’s what I’d do:

• Drive it until the tank is down to about 1/4 tank or less
• Add a full 16 oz can (or even 2 cans)
• Drive it 10–20 miles (or until nearly empty) before refueling

Fuel that sits can form gum and varnish, which is the #1 cause of rough running after storage. Sea Foam works to liquefy and clear that out to help your engine maintain or recover strong performance.