For better or worse, most of the gasoline you can buy at stations around the U.S. has been “oxygenated” with some kind of additive since a series of amendments were made to the Clean Air Act in the 1990s. The idea is to help the gasoline burn more completely, and thus cut down on harmful emissions. The latest additive is ethanol, which — without getting into the political and environmental debates about its efficacy — is fine for use in fuel-injected vehicles that are run regularly and designed to use up to 10% ethanol (85% in flex-fuel vehicles).

On the other hand, ethanol-oxygenated fuel is not so great for any vehicles that sit between uses, and/or carbureted engines, like the one in your dirt bike or older motorcycle. Ethanol is alcohol, and alcohol is corrosive to certain parts in older fuel systems. Alcohol is also “hygroscopic” and likes water, so when water gets into fuel during a fill-up or from condensation, it can mix with the ethanol, creating a chemical combo that causes rust, corrosion, acids and sticky varnish that wreak havoc in fuel systems, especially carburetors. Ethanol can even cause rubber parts and fuel lines to dry out, harden and deteriorate prematurely.

Alternatives are few — unless you’re lucky enough to have a fuel supplier or gas station near you that sells ethanol-free gasoline (see pure-gas.com or buyrealgas.com), or you’re OK paying $15-$18 per gallon for ethanol-free gas in cans from a dealer (see vpracingfuels.com), most of us are stuck buying gasoline oxygenated with 10% ethanol. Again, your modern fuel-injected vehicle that you store in a dry place and run at least twice a month is unlikely to suffer any ill effects, but what should someone do with their older carbureted bike (or boat, lawnmower, string trimmer, generator, etc.)?

The simplest, best advice I can offer is…don’t let them sit. The shelf life of unstabilized gasoline containing ethanol is about one month. Running your vehicles every week — or two maximum — until fully warm is the best way to prevent fuel delivery problems. When you can’t run them, here’s what I do to minimize (not eliminate!) problems with my small collection of bikes, and my generator, string trimmer and lawnmower, even spare fuel in cans.

Half Full, Half Empty

On carbureted bikes with steel gas tanks, half the fuel system should be drained, and the other half kept full. Carburetors and their tiny air passages and jets can become plugged with aged fuel that deteriorates into sticky varnish over time. Since carb internals are made of non-ferrous aluminum, brass, plastic and rubber that won’t rust, if it’s practical to drain them (shut off the gas manually first or look for a vacuum-operated-type petcock that is off whenever the bike is), this is your best bet for trouble-free operation when refilled. O-rings and seals have been known to dry out and leak when carbs are left dry for a very long time, but this is less likely than plugged jets or worse if they’re left wet.

Some carburetors have a drain bolt in the bottom of their float bowls, others have a drain screw. Don’t overtighten either one, and only drain carburetors (into something please, not just onto the bike and floor) when the bike is off and cold. Don’t run the bike until it dies to suck the rest out — this can draw dirt and debris from the bottom of the float bowl into the carburetor. I once bought a Honda multi that had been stored in a basement for 15 years with the carbs drained and stabilized fuel kept in the tank, and it was rust-free and fired right up without carb service. If you’re careful, there’s no reason you can’t return newer, clean drained fuel to the tank.

Steel tanks on carbureted or fuel-injected bikes can rust inside, so it’s best to leave them at least ¾ full of fuel to which you have added stabilizer (more on this later). Some newer models have plastic-shrouded aluminum or plastic tanks, in which case it’s up to you, but make sure you stabilize it if you leave fuel in the tank. In really humid environments I would still keep an aluminum tank full.

Fuel injection systems seem much less susceptible to the ravages of stale fuel, and once full of stabilized fuel are almost carefree. In fact, some manufacturers warn against running their EFI bikes entirely out of fuel.

If you can’t drain carbs, after adding stabilizer to the fuel in the tank run the bike long enough to insure stabilized fuel has filled them, then shut off the bike and petcock. I carry a small bottle of stabilizer with me when I take out one of my less frequently ridden bikes, and add it at the gas station before riding home. Err on the side of adding more stabilizer; you can’t overdose (within reason) with the products mentioned below. Stabilized fuel in the carbs does not guarantee that they won’t suffer from plugged passages or jets, however, and you should still run bikes kept this way at least every three weeks. More often is simple insurance that you won’t need an expensive service — compare the cost of non-ethanol race gas and/or stabilizer to that of a carburetor rebuild and the former start to make economic sense. Just make sure you run the engine until it’s fully warm (to burn off water and contaminants in the oil and exhaust). While you’re at it, pump the fork and shocks and work the brakes, clutch and shifter to keep seals flexible and lubricated.

A Stable Relationship

A good ally in the fight against bad gas and fuel delivery issues is fuel stabilizer. They’re not foolproof, but three we’ve found to provide consistent results with motorcycles are Star Tron Enzyme Fuel Treatment, Spectro FC Premium Fuel Conditioner & Stabilizer and Bel Ray All-in-One Fuel Treatment. There are others, but we lean toward these simply because they include motorcycles in their literature and FAQs and that gives us a warm, fuzzy feeling. All make lots of claims about their effectiveness that we have no way of proving or disproving, so just buy some and use it, or spend hours online researching them before you just buy some and use it. All of them offer smaller bottles and/or containers with measuring devices built-in to make carrying and using it while out on the bike easier.

The instructions for each will tell you how much to use, how long the fuel is usable when treated, etc. There are some consistent rules of thumb. You generally only need to stabilize fuel if you won’t use it all up within two months (but carbureted bikes should still be run every couple of weeks as described above). Adding a little new gas or stabilizer to old gas won’t renew it, nor will adding more stabilizer to old stabilized gas extend its usable life. Overdosing is not an issue (unless you drink it, duh), and in my experience none of them will cure a plugged-up carb no matter how much you add to the fuel. Your best bet is to avoid plugging it in the first place.

Good luck, and please write me with any questions, comments or dissimilar experiences! [email protected]

Source: RiderMagazine.com

Take a look around any dealership floor, bike night parking lot or race paddock, and the vast majority of motorcycles will be wearing a chain and sprockets for their final drive. Belts and driveshafts have their perks, but chains are the dominant drivetrain thanks to their low production cost, efficient power transmission and easy gearing changes and component replacement.

Chains basically come in two categories: unsealed or standard roller chain, and sealed or O-ring chain. Unsealed chains are commonly found on vintage bikes, small-displacement economy rides and off-road motorcycles. They’re what you see on bicycles and conveyor belts, and even the treads on a bulldozer are a type of unsealed chain. Standard chain is just a series of plain bearings made of metal links and nothing else. That means it’s up to you to apply lubricant to keep the parts from grinding themselves into dust, and you have to do it every few hundred miles. Even then, reducing friction between high-wear components like the link pins and bushings is difficult, and as a result unsealed chains wear quickly, necessitating frequent slack adjustments and replacement.

Sealed chains, as the name suggests, have rubber seals sandwiched between the side plates and inner links, sealing in grease that’s sucked in around the pins via vacuum when the chain is manufactured. The O-rings seal the grease in and keep dirt and water out, ensuring the pins and bushings are bathed in lube, which greatly reduces wear and extends the life of the chain. This arrangement also means less frequent and lighter applications of chain lube, since all you’re doing with that can of aerosol is keeping the O-rings moist and pliable and preventing the metal links from corroding.

Sealed chains were introduced in the late 1970s and revolutionized chain maintenance by greatly reducing the need for lubrication while simultaneously increasing the life of the chain by up to tens of thousands of miles. More recently, other seal styles have been developed, most notably the X-ring. Here’s the idea: When that chubby little O-ring gets squeezed between the plates, it creates a fair amount of surface area that results in a small amount of drag every time the chain link pivots. That drag saps power getting to the rear wheel. With an X-ring chain, the sealing ring’s profile resembles an “X”” The X-ring is more readily compressed between the plates, and its shape provides four sealing surfaces around each link pin (instead of two), but with less total surface area, resulting in less drag.

If evaluating the drag on your chain seems like the kind of obsessive minutia only a racer would think about, you’re right. X-ring technology was developed for the track and adapted for the street, where the better sealing of the X-ring helped increase chain life even more. As a track-bred product, X-ring chains are typically made from harder, stronger metals and may have weight-reducing features like hollow link pins and thinner side plates. With all those virtues, however, comes a higher price.

Generally speaking, the better sealing (and thus service life) a chain offers, the more expensive it’s going to be. That being said you may be tempted to slap a standard unsealed chain on your bike because it’s cheap, but the upfront savings simply isn’t worth the cost of increased maintenance and more frequent replacement. Unsealed chains still make sense on smaller, less powerful machines that will log fewer miles, but for regular road use a sealed chain–whether it’s an O-ring type or some other variety–is definitely the way to go.

Sealing lube in around the critical wear components of the chain has taken what was already a practical, reliable and efficient drivetrain and made it even better. No wonder the majority of motorcycles rely on links and sprockets to get down the road.

Source: RiderMagazine.com