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· Registered
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Discussion Starter · #1 ·
I just bought an older boat with an Atomic. The marina dropped new deep cycle batteries in, and the engine turned over but before I do anything else I'm sure I need to get that old gas out of the tank, and as much from the fuel filters as possible. Any suggestions on the best way to do this?

Thanks Much

· Well-wisher
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A4's have either a mechanical or an electric fuel pump. Take a look at Moyer Marine ( if you would like a photo to see what they look like.

If you have an electric pump, remove and route the fuel line from the motor to a gas can, pull the coil plug out of the distributor cap, and turn on the motor. An extra piece of fuel line will come in handy, as well as a couple of extra gas cans, should you have a relatively full tank.

If you don't have an electric pump, a siphon is your best bet. Harbor freight sells them or you can find one in for fish tanks in many larger stores.

I would recommend bringing along a clear container and putting the first liter or so in for inspection. Look for water settling to the bottom and check the fuel for color. If it looks pretty good (no water, no particulate matter, not dark and varnished), I'd try to run it. A4s, like tractor motors, can handle somewhat old fuel, if it's been well kept.

With older boats, the fuel lines won't necessarily be USCG-reg hose. New fuel line is easy to install and USCG reg hose will be something on any surveyor's list.

Finally, take the time to replace the other wearable items (cap, rotor, plugs, points) and clean the carburetor before you get too excited. Any one of those can still make your motor run rough or not at all.

A well-kept A4 is a wonderful thing and not to hard to achieve.

· 1975 Newport 28
1986 Hunter 31
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One thing to keep in mind is that most A4s with electric fuel pumps have an oil pressure sensor switch on them that prevents the fuel pump from running if there's not at least 10 psi of oil pressure. You can tell if this switch is in line by following the power lead from the pump to see if it goes directly to power or to a switch screwed into an oil line fitting.

If the lead does go to the switch, you can just bypass it by running a suitably sized lead from power directly to either the fuel pump or the "power" side of the switch, whichever is more easily accessible. On my boat I have a bypass switch mounted inside the engine compartment that lets me bypass the oil sensor if necessary. It comes in handy for testing the pump, and especially so if the sensor switch decides to fail when you need the engine.

Good luck!

· Tundra Down
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I cleaned up the fuel tank on my A-4 powered I-28 last spring. It was a simple fix. I purchased an inexpensive automotive fuel pump($15.00) and some fuel line at the auto parts store and pumped out the tank along with several rinses using some chemicals I purchased at Wallmart. I connected the pump to the fuel line that normally goes to the primary fuel filter from the tank

BE VERY CAREFUL I made sure that there were no potential spark sources from the pump's wiring inside anywhere. I wired it to a separate battery that was up on the coaming. I had the boat wide open and pumped the fuel I was rinsing with into a bucket with a small opening to avoid fumes. I think I went through 4 "rinses" allowing the chemicals to sit in the tank between pump outs for what ever was a convenient time, sometimes just overnight. It did take me about 20 gallons to be happy that I had a clean fuel tank. Doing this on your mooring can add helpful motion to the contents that are doing the cleaning. I installed a new Racor filter as my primary and a polisher after that. I have had no problems.

The carb on the A-4 has small jets and a very small particle can cause problems. Spending a few dollars on a pump and the gasoline was cheap insurance against having some grit show up during a rough ride when you need an engine to enter port.
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