There are many things that can go wrong with your dirt bike, one of which would be your Fuel to air mixture and if you’re running a four stroke in high elevations, you may quickly encounter this problem. This mixture may make or break your race, day, or even weekend so make sure you understand what is going on inside your dirt bike before playing around with these fuel components.
Depending on where you are riding at, you will need to play around with your air to fuel ratio. This ratio can be tampered with by many variables. It could be as minor as a colder morning that has more oxygen in the air, or as drastic as a large change in elevation. Many of the race teams adjust their air or fuel screws to accommodate for temperature and humidity, and use a histogram to help make those adjustments more precise.
Depending on what type of dirt bike you have regulates which type of screw you will be adjusting. If you are rocking a 2 stroke, the air screw is the one you will be looking for, but if you have a 4 stroke than you will be adjusting the fuel screw. The reason why the bikes have different screws is because 4 strokes do not have the same engine vacuum as 2 strokes. 2 strokes create more engine vacuum ultimately sucking in more fuel from the float bowl of your carb. Depending on the variables like elevation, temperature, humidity and time of day, you will be tampering with this screw to get the right ratio on your bike and allow the optimal amount of air into the pilot circuit.
The Fuel Screws do the opposite and drag more fuel in and allow for more finite tuning in these low vacuum situations; hence why they are used in 4 strokes. Same rules apply for this screw as the air screw, as they both allow for the bike to run at optimal levels of performance. Any changes in elevation over 4,000 feet will have a drastic effect on the mixture and will need some tuning to get your bike running properly again.
Types of Fuel Screws
We offer a wide variety of fuel and air screws for our customer, and the most recommended one is the adjustable fuel screw. This type of fuel screw is made by handfuls of companies like Pro Circuit, Factory effex, Works Connection and more. The difference between a standard fuel screw and an adjustable fuel screw is that the standard fuel screw requires a fuel screw screwdriver (they are much smaller than ordinary screwdrivers) in order to make the adjustment whereas the adjustable fuel screw is able to be adjusted by your hand. The Fuel Screw is located under the carb making it difficult and irritating to reach and adjust, with the adjustable fuel screw this is a thing of the past as.
Along with the fuel screws, we also have carburetor rebuild kits that come with everything you need like jets, needle jets, main jet, pilot jet, fuel screw, float valve needle and seat, gaskets and O-rings. All Balls is one of the companies that makes these rebuild kits and you can find them on sale now! Along with this other fuel component, we also have accessories that allow you bike to run at its maximum performance.
Lightspeed makes a vast selection of dirt bike accessories that allow them to have more protection, and thanks to their carbon fiber construction they are lighter than any other similar aftermarket part you can find. The Lightspeed Carbon Fiber understands heat shield and the Carburetor heat shield are some of their accessories available. Both products mitigate the amount of heat transferred to the fuel which can cause a loss of power and performance. With these shields, your dirt bike will run cooler and most people know that cooler temperatures equals larger combustion ultimately resulting in an increase in power. These parts may not increase horsepower, but they will definitely help prevent the loss of it!