The oil is changed. New filter too. Air filter is clean and the coolant is fresh. You just added a screaming new pipe and the tires look so slick you question whether to ride them or display in your man-cave.
Bottom line - you're ready to ride and compete for a shot at the podium.
Now you just need the right Motocross gas and there's not a specialized pump station at the track.
There's an ARCO, Chevron, and Costco on the way out of town. But you've got an allegiance to Shell a mile out of the way. Even further - a mom and pop stop actually offers race fuel.
So what gas should fill that five-gallon jug?
The easy answer is any and all of the above work for your 4-stroke or blend with premix for a 2-stroke. Whether you go the cheap route and grab some 87 octane or think a few bucks more for the 92 premium Techron infused ammunition glides you along faster it all pretty much does the same thing.
It starts your engine and gets you around the track.
Perhaps you've noticed the tank truck refilling one gas station's underground fuel storage reservoir looks just like the one you saw a few days earlier at a competitor's lot. That's because, generally, every gasoline company gets their gas from the same pipeline. Of course, once in-hand, Oil Company A adds a special detergent while Oil Company B adds one of their own, each touting the performance benefits of their product. Then they hire the same distribution company to provide the fuel to individual stations.
We won't debate the merits of the additives. Besides, whatever is added post-production ain't much. But, some people swear their cars, or their dirt bikes, run better on fuel from one company compared to what's offered from another or higher octane burns smoother than the cheaper stuff. What we're saying is don't run yourself mad tinkering with different fuels for that racing edge. Fiddling with the tire pressure makes more of a difference than the gas used on race day.
As for racing fuel it's expensive, smells pretty good and if you're reading this it's unlikely to provide any benefits because mostly the pros have the means, the skills and bike set-up to squeeze out the minor performance gain from racing fuel. When you're facing the best riders in the world at an Outdoor National, racing fuel indeed might be the difference between first and second. But when you're lining up alongside local amateurs and weekend warriors, the money saved on regular 87 octane gas helps buy an aftermarket upgrade part that serves you much better on the track than racing fuel.
Mechanic's Note: If your dirt bike or ATV engine is tuned to run at a higher octane you'll need to invest in higher octane fuel. For example, a higher compression piston could cause the fuel to detonate (causing knocking) rather than burn which affects performance. Check the owner's manual. Most non-ethanol based fuel is rated at 90 octane and recommended for Motocross bikes.
One type of gas to avoid, if at all possible, is ethanol-based. Yes, it is difficult nowadays to find gas that's not corn fed especially in certain parts of the country or during a specific time of year. If you have a choice, pay extra or go out of your way for straight-up gas, otherwise it's OK to use the ethanol-based. It works just fine and won't hamper performance. However, we advise NOT using an ethanol concentration above 10 percent.
The big concern using ethanol-based fuel is corrosion. Ethanol attracts moisture which overtime corrodes vital engine parts. Therefore, burn off all ethanol-based fuel in the tank, drain the tank or add a fuel stabilizer if left in the tank for long periods. Ethanol-based fuel eventually gels and clogs the jets.
So, what about premix? We'll leave that discussion for another day. Come back soon to read about what premix to use with whatever gas you picked up on the way to the track.
Told you we'd cover premix! Check out What 2-Stroke Premix to Use in Your Dirt Bike or ATV.
Written By: AndrewT