You just acquired a new dirt bike and are wondering what fuel to use. Researching online or asking those around you can bring confusion. You don’t want to ruin your dirt bike by using the wrong fuel.
Dirt bikes take gasoline rated between 87 and 93 octane. There are two types of engines on dirt bikes, a 2-stroke, and a 4-stroke. The type of fuel you use will be determined by the engine your motorbike has.
The type of gas you use in your dirt bike can affect its performance. In this post, we will discuss the 2-stroke and 4-stroke engines and what type of gasoline can be used in them as well as what gas is most efficient. We will also help you determine what type of engine you have.
There are a few ways to learn what type of gas a dirt bike takes. The simplest way is to inspect the gas tank area to determine the specified gas type. Another way is to read the owner’s manual. If you do not have an owner’s manual, research your bike by its VIN number.
There are many dirt bike manufacturers. If you know the brand of dirt bike you have you can do a google search to find the company and research your motorbike by the VIN. The vehicle identification number is located on one of three places
This is a seventeen-digit number that will tell you all about your dirt bike. You may need to search the area close to find the VIN or move the handlebars from side to side while looking. Go to a free site on your computer such as VINCheck to research your Dirt Bike and get your owner’s manual.
If your motorbike has its original gas cap it will often tell you what your dirt bike requires. It will say
- Fuel Only
- Unleaded Only
- It may be a number ratio such as 40:1
- It might show an oil can and gas pump.
The ratio mix is the manufacturer’s recommended gas to oil combination. If you see writing on your gas cap or on the tank itself, read it and follow the directions.
A four-stroke engine uses gasoline for fuel. There are three types of unleaded gasoline that can be used in a 4-stroke Motorbike. These are
These numbers coincide with the performance of the octane rating in gasoline. The higher the number the better the performance.
The octane scale of gasoline expresses the stability of the gasoline. That means the lower the octane rating the more likely the gasoline is to ignite with the pressure exerted in a test engine.
Lower octane is associated with engine knock because it can create uncontrolled secondary combustion in the cylinder. This uneven disbursement of energy can reduce performance and could eventually cause damage to the engine. (source)
Even though the higher octane gasoline is considered more stable and thus provides better performance, it is much more expensive to buy. Unless you are using your dirt bike in competitions, you can forgo the higher octane gasoline and fill up with regular unleaded.
Regular unleaded is typically rated at 87 octane. It is the lowest octane available at the pump and it is the least expensive. Mid grade unleaded, also known as super unleaded gasoline provides better performance with an octane level between 89 and 90.
A 4-stroke engine does not require a mix of gasoline and oil. Mixing large amounts of oil into the gas in a 4-stroke engine can cause damage to your engine. This will result in bad performance due to the clogging of the spark plug.
If you want your dirt bike to perform well it is recommended that you do not use an oil and gas mixture. Just use plain gasoline when filling your tank. For best performance use a higher grade unleaded gasoline. (source)
Two Stroke dirt bikes require gasoline with some oil mixed into the gas tank. The manufacturer of the dirt bike will typically have their recommended mixture ratio printed somewhere on the gas tank or cap. This information is also found in the owner’s manual.
The best type of gasoline to use in a two-stroke dirt bike engine is ethanol free with a rating of 90 or higher octane. However, you can get away with a lower octane fuel, such as an 87 octane rating.
If you are looking for performance, then it is perfectly acceptable to mix a high octane-rated pump gas with racing fuel to give your dirt bike a gas with an octane of over 100. (source)
When you get gas for your 2-stroke engine you will mix it with a two-stroke engine oil
A two-stroke Motorbike engine requires an oil and gas mixture to perform correctly. Unlike a 4-stroke engine, the 2-stroke engine does not have a separate oil reservoir. If oil is not mixed into the fuel there will not be enough lubrication for the engine. This will kill the engine
Your dirt bike needs a gas and oil mix to perform correctly. You will need
You will need to know the correct mix ratio before mixing the oil and gas. This can be found in your owner’s manual. You will have to do some math in order to find how much oil should be used per gallon of gas.
Here’s a helpful video showing how to mix gas for a 2-stroke:
This is done by taking your gas-to-oil ratio and doing some dividing. If your Dirt Bike requires a 40:1 mix that means it needs 40 parts of fuel to 1 part of the oil. A gallon of gas is 128 fluid ounces. To find how much oil you will need, divide 128 by 40.
This will give you 3.2 ounces. So, for each gallon of gas, you will require 3.2 ounces of oil mixed into it. This formula will work for any gas and oil mix ratio for dirt bikes. Even though the amount of gas may change, the oil ratio is always going to be one.
If you do not want to do the math you can use a calculator to find the oil ratio. You can also just use the oil measuring cup suggested as it has pre-mixed ratios on the cup.
Whether your motorbike is a 2-stroke or 4-stroke, it is necessary to drain any leftover gas before storing it for any length of time. This is because the fuel will degrade when sitting. You can add a fuel stabilizer to protect your engine from ethanol corrosion.
I recommend this Fuel Stabilizer for 2-Stroke on Amazon.
A fuel stabiliser is especially useful in 4-stroke engines that do not have the added benefit of the 2-stroke oil. Be sure to add the stabiliser before adding the gas so it will mix well.
Dirt bikes take unleaded gasoline. Dirt bikes with a two-stroke engine need to have two-stroke oil added to their fuel. Using high octane gasoline will provide better performance in either type of dirt bike engine, but it is not necessary.