If your devilbiss generator fuel tank has started weeping gas or looks like a rusted-out mess inside, you're probably realizing that these old-school machines are built like tanks, except for, well, the actual tank. It's a common headache for anyone who owns one of these classic workhorses. These generators, many of which were sold under the Porter-Cable or Ex-Cell brand names back in the day, were built to last decades, but the metal fuel tanks were always the weakest link in the chain.
Usually, you notice the problem after the generator has been sitting in the back of the shed for a season. You go to pull the cord, and you're hit with that sharp, sour smell of old varnish—or worse, you see a damp patch on the concrete. Once a metal tank starts to go, there's really no "patching" it for the long term. You're better off just swapping it out and moving on with your life.
Why These Tanks Tend to Fail
Most original equipment on these units was a stamped steel tank. Steel is great for durability if you're hitting it with a hammer, but it's terrible when it comes to modern ethanol-blended gasoline. Ethanol is hygroscopic, which is just a fancy way of saying it loves to suck moisture out of the air. When that moisture settles at the bottom of your devilbiss generator fuel tank, it creates a little pocket of corrosion.
Over time, that corrosion eats through the lining. You might not even see it at first. It starts as "pinholes," tiny little punctures that let just enough gas out to be dangerous but not necessarily enough to create a puddle immediately. If you look inside with a flashlight and see orange flakes or a textured, rough surface, that tank is a ticking time bomb for your carburetor. All that rust eventually breaks loose and clogs up your fuel jets, leaving you with a generator that won't stay running when you actually need it.
Finding the Right Replacement
Finding an exact OEM replacement can be a bit of a scavenger hunt. Since Devilbiss Air Power Company went through various ownership changes over the years, the original part numbers can be a nightmare to track down. However, the good news is that these generators often used fairly standard mounting patterns.
When you're looking for a new devilbiss generator fuel tank, you don't necessarily need one that says "Devilbiss" on the box. You need one that matches the capacity—usually 5, 6, or 7 gallons—and the bolt hole dimensions. Most of the 5000-watt to 7000-watt units used a rectangular tank with four mounting points.
Pro tip: Measure the distance between the mounting bolts from center to center. If your measurements match the replacement you're looking at online, you're 90% of the way there. Also, check which side the fuel outlet (the petcock) is on. You don't want to buy a tank only to realize the fuel line has to stretch across the hot engine block to reach the carb.
Making the Switch to Plastic
A lot of people ask if they should stick with metal or go with a high-density polyethylene (plastic) tank. Honestly? Go plastic if you can find one that fits. Modern plastic fuel tanks don't rust, they handle ethanol much better, and they're usually a bit lighter.
The only downside is that plastic tanks can sometimes be a bit thicker at the mounting points, so you might need slightly longer bolts than what came with your original metal devilbiss generator fuel tank. But that's a small price to pay for never having to worry about rust flakes in your carburetor ever again.
The Swap-Out Process
Changing the tank isn't exactly rocket science, but it's a messy job if you don't plan ahead. You'll want to do this outside in a well-ventilated area—no, your closed garage does not count.
- Drain the old fuel: If there's still gas in the old tank, get it out. Use a siphon or just unhook the fuel line at the carburetor and let it drain into a dedicated gas can.
- Disconnect the lines: Most of these units have a simple rubber fuel line held on by a pinch clamp. If your fuel line feels crunchy or stiff, throw it away. It's cheap to replace, and it's not worth risking a leak.
- Unbolt the tank: There are usually four bolts holding the tank to the generator frame. Keep the rubber grommets if they're still in good shape. Those grommets are important because they vibrate. If you bolt a metal tank directly to a metal frame without rubber spacers, the vibration will eventually crack the tank or the frame.
- Transfer the hardware: If your new devilbiss generator fuel tank didn't come with a fuel cap or a petcock, you'll have to move them over from the old one. This is a great time to install a new fuel filter.
Don't Forget the Fuel Valve
While you've got everything apart, take a close look at the fuel shut-off valve (the petcock). If your old tank was rusty, that valve is likely full of junk too. Most Devilbiss tanks use a valve that threads into the bottom of the tank with a small screen attached.
If that screen is torn or covered in gunk, just buy a new one. They're universal and cost very little. Having a fresh tank with a dirty old valve is like putting on clean socks without washing your feet—you're just asking for trouble down the line.
Keeping Your New Tank Healthy
Once you've got your new devilbiss generator fuel tank installed and everything is hooked up, you want to make sure you don't end up in the same spot three years from now.
- Use fuel stabilizer: If the generator is going to sit for more than a month, add a stabilizer. It keeps the gas from breaking down and becoming acidic.
- Keep it full or keep it empty: This is a debated topic, but for metal tanks, keeping them full reduces the amount of air (and moisture) inside. For plastic tanks, it matters less, but it's still good practice.
- Check the vent: Make sure the gas cap is venting properly. If the vent gets clogged, the engine will start, run for ten minutes, and then die because a vacuum has formed inside the tank.
Is It Worth the Effort?
You might be wondering if it's even worth spending $100 or $150 on a new tank for a machine that's fifteen years old. In the case of Devilbiss generators, the answer is usually a loud "yes." These units often used heavy-duty engines (like the Honda GX series or the older Briggs & Stratton Vanguards) that are significantly better than the cheap "disposable" generators you see at big-box stores today.
By replacing the devilbiss generator fuel tank, you're basically giving the machine a second life. It's a simple Saturday afternoon project that saves you from spending $800 on a new unit that probably won't be built as well as the one you already have.
Just take your time, measure your mounting holes carefully, and don't forget to replace those old fuel lines while you're at it. You'll thank yourself the next time the power goes out in the middle of a storm and your old reliable Devilbiss fires up on the first pull. It's all about that peace of mind, knowing the fuel system is clean and the gas is actually staying where it's supposed to be.