Husqvarna chainsaws feature two-stroke engines that run best when provided with the proper ratio of fuel and two-stroke engine oil. The fuel mixture must meet the manufacturer's standards and isn't the same as the gas you put in your car. If you use any other type of fuel, serious damage to the engine can occur.
The recommended gasoline in a Husqvaran chainsaw is regular unleaded gasoline. The engine needs a gasoline with an octane rating of 90 or higher for the it to run properly. The higher grade gasoline helps combustion in the cylinder and reduces the wear on the piston. Using gasoline below 90 octane will not provide adequate engine protection. Gasoline with additives or blends, such as ethanol or other alcohols, should never be used as a fuel source. This can severely damage plastic parts inside the carburetor.
The piston's two-stroke movements needs proper lubrication, and since the oil doesn't come from a pump, it needs to come directly from the fuel source. Two-stroke engines, like a Husqvarna, require an air-cooled two-cycle engine oil. Husqvarna manufactures its own brand of two-stroke engine oil and recommends using this in their chainsaws because they have tested the engines using this oil. If you can't find Husqvarna engine oil, use another high-quality oil intended for air-cooled two-cycle engines.
Recommended Mixture Ratio
Husqvarna also recommends a specific ratio of gasoline to oil for their saws. This mixture is 50-to-1 gasoline to oil for all two-stroke engines. Every gallon of gasoline requires a 2.6 fl. oz. bottle of two-cycle engine oil. This ratio has been formulated to give the engine the highest level of performance. Deviating from this mixture ratio will increase the likelihood of engine damage and failure. It also decreases power and acceleration in the engine.
Mix the oil and gasoline thoroughly to blend it properly. Pour the two-cycle engine oil into the empty container before mixing in the gasoline. This will allow the oil to break up as the gasoline gets dumped in. After the gasoline is topped off, shake the can vigorously for at least one minute to blend it all together. This mixture goes bad after 30 days, so only mix what you can use in that time.