If you're currently hunting for a 1985 honda big red 250es gas tank, you're probably already well aware of how tough these can be to find in decent condition. These machines are absolute legends in the ATV world—mostly because they refuse to die—but if there's one Achilles' heel to the Big Red, it's the fuel system. After nearly forty years of sitting in barns, sheds, or out in the elements, the original metal tanks have usually seen better days.
Most people who pick up a vintage 250ES project find themselves facing the same problem: a tank full of orange sludge and rust flakes that look like cornflakes from a nightmare. It's a common hurdle, but it's one you've got to clear if you want that 250cc engine to purr the way Honda intended back in the mid-80s.
The Struggle with Old Metal Tanks
The 1985 model year was a big deal for the Big Red. It was the first year of the 250ES, which brought that glorious shaft drive and electric start to the party. But Honda stuck with a steel gas tank, and while steel is tough, it's not exactly a fan of modern ethanol fuel. If a 1985 honda big red 250es gas tank sits even a quarter full for a few years, condensation builds up on the inside. That moisture sinks to the bottom, and before you know it, you've got pinholes eating through the metal.
If you're looking at your tank right now and seeing bubbles in the paint near the bottom edges, that's usually a sign that the rust is working its way from the inside out. It's frustrating because the rest of the bike might be mint, but that leaky tank makes it a fire hazard and a headache. You've basically got two paths here: you can try to save the original metal, or you can go the route of a modern replacement.
Choosing Between OEM Metal and Aftermarket Plastic
This is the big debate in the Big Red community. Do you keep it original, or do you go for reliability?
Why Go Metal?
If you're a purist and you want your Big Red to look exactly like it did on the showroom floor in 1985, you're going to want an original metal 1985 honda big red 250es gas tank. There's something about the weight and the "clink" of a metal tank that just feels right. Plus, the original tanks have those specific body lines and the mounting points for the factory decals that just look "correct."
The downside? Finding a "new old stock" (NOS) tank is basically like finding a unicorn. If you do find one, be prepared to pay a small fortune. Most people end up buying a used one on eBay, which often ends up having its own set of hidden rust issues.
Why Switch to Plastic?
For the guys who actually use their Big Reds for work, hunting, or trail riding, a plastic aftermarket tank is often the way to go. Companies like Clarke Manufacturing have been making these for years. The biggest perk is obvious: plastic doesn't rust. You can leave modern pump gas in there all winter, and you won't come back to a mess of rust in the spring.
The trade-off is the look. Plastic tanks are slightly bulkier, and the color might not be a 100% perfect match to the Honda Fighting Red. You also can't always get decals to stick to plastic as well as they do to metal because plastic tanks "breathe" slightly, which can cause stickers to bubble over time.
How to Clean Out Decades of Gunk
If your 1985 honda big red 250es gas tank isn't leaking yet but is just full of gunk, you might be able to save it. I've seen guys use everything from white vinegar to industrial-grade acid to clean these things out.
A popular "old school" trick is the nut-and-bolt method. You take the tank off, pull the petcock out, and dump in a handful of stainless steel nuts and bolts or even some heavy-duty gravel. Then, you wrap the tank in a bunch of old blankets, toss it in a clothes dryer (with the heat off!), and let it tumble for an hour. The movement knocks all the loose scale off the internal walls. It's loud as heck, and your spouse might hate you for it, but it works surprisingly well.
After you get the big chunks out, a long soak in white vinegar for a few days can eat away the remaining flash rust. Just make sure you rinse it thoroughly with water and then immediately hit it with a bit of gasoline or a fogging oil so it doesn't flash-rust again right away.
Dealing with Pinholes and Leaks
So, what if you've got those dreaded pinholes? It's not necessarily the end of the road. There are internal tank sealers like Red-Kote or POR-15 that can work wonders. The key here is preparation. If you don't get the inside of that 1985 honda big red 250es gas tank surgically clean and bone dry, the sealer will eventually peel off. When that happens, it turns into a gooey mess that will clog your carburetor faster than you can say "three-wheeler."
If the holes are bigger, some guys will actually weld or braze the tank. If you go this route, please be careful. Gas fumes are no joke, and "empty" tanks are often more dangerous than full ones. I've heard too many stories of tanks popping like balloons because someone didn't purge the fumes properly before hitting it with a torch.
Swapping the Petcock and Lines
When you're messing with a 1985 honda big red 250es gas tank, you absolutely have to look at the petcock. The original ones have a tiny little screen (the fuel strainer) that sits inside the tank. On the 250ES, these are notorious for getting brittle and disintegrating.
If you're putting in the work to clean the tank, don't put an old, crusty petcock back on. Spend the twenty bucks and get a new one. While you're at it, replace the fuel lines. Modern fuel lines are much better at handling the ethanol in today's gas. I always suggest adding a small inline fuel filter, too. It's cheap insurance to keep any microscopic bits of rust from reaching that sensitive Keihin carb.
Making It Look Factory Fresh
Once the structural stuff is handled, you probably want it to look good. If you've stuck with the metal tank, you're looking at a paint job. The color code for the 1985 Big Red is usually R-124H (Fighting Red). Getting a high-quality fuel-resistant clear coat is the most important step here. If you spill a little gas while filling up—which we all do—regular spray paint will bubble and peel instantly.
Applying decals is the finishing touch. The 1985 Big Red had those iconic blue and white stripes. When you're putting them on your 1985 honda big red 250es gas tank, use a little bit of soapy water so you can slide the decal into the perfect position before it sets. It makes the whole process way less stressful.
Final Thoughts on the Big Red Tank
At the end of the day, the gas tank is the heart of the fuel system on these old machines. Whether you decide to scrub out the original metal or swap it for a worry-free plastic version, just getting rid of that old rust is going to make your Big Red run a thousand times better.
These 250ES models are getting harder to find every year, and they're only going up in value. Taking the time to do the tank right isn't just about making it run; it's about preserving a piece of off-road history. Plus, there's nothing quite like the feeling of clicking that big red starter button and hearing it fire up on the first rotation because it's finally getting clean fuel. It's a lot of work, sure, but for a 1985 Big Red? It's always worth the effort.