The Oil-to-Gas Ratio for the Craftsman 2.0 Chainsaw
The Craftsman 2.0 chainsaw, as with all gas-powered Craftsman saws, requires mixed fuel for combustion. This fuel combines gasoline and an engine oil, which lubricates the piston and crankcase during operation. Without this specific amount of engine oil, the piston would overheat and blow out the cylinder, ruining the seals, piston and crankcase.
The engine needs oil to keep the crankcase lubricated to keep the piston moving at high speeds. Unlike cars or boats, the Craftsman 2.0 chainsaw doesn’t use an oil pump to deliver oil into the crankcase. This oil, designed especially for two-stroke engines, will break apart evenly inside the gasoline, so when it combusts, a small amount of residual oil develops on the cylinder walls and on the crankshaft. If possible, use only oil recommended for use in two-stroke air-cooled engines, which will evenly separate. However if no chainsaw oil is available, mix the fuel with new SAE 30 engine oil.
The Craftsman chainsaw runs at high speeds, often higher than 10,000 RPM, so it needs a higher-quality gasoline to keep the piston at the right operating temperatures. A gasoline graded at 87 or higher is generally recommended for use in the 2.0 chainsaw. However, this fuel grade isn’t an absolute requirement, but it will increase the performance and life of the engine. Never use gasoline with other additives, such as ethanol or gasohol, and never use diesel gasoline for the mix.
The Craftsman 2.0 chainsaw is an older model of chainsaw, so it’s likely that some — if not all — of the fuel components in your chainsaw are dirty or restricted. If you haven’t done so, replace the entire fuel lines and pickups, and clean the carburetor thoroughly, which will allow you to get a better, leaner fuel mixture into the engine. While Craftsman recommends a gas-to-oil mixture of 32:1 up to a 40:1 mixture, other factors, such as air quality or elevation, may alter the required amount of oil for your engine.
Finding Right Mixture
Getting the right mixture for your 2.0 chainsaw in your area will take some trial and error. Mix a batch of gasoline on the richer side of the scale, starting at about 30:1. Run several tanks of gas with this mixture, and monitor the engine performance during acceleration, idling and power at full load. If the engine is sluggish or drops under load, lean the formula up to the higher end of 40:1. If you’re at a higher elevation, you may need to lean the formula up to 50:1, though this will put added pressure on the engine and may cause damage.