Chainsaw Oil Ratio Can Vary By Manufacturer
The mixture used in all two cycles engines can vary by manufacturer and users should simply assume that because all of their outdoor power equipment requires an oil and gas mixture that the ratio will be the same. For most manufacturers, the chainsaw oil ratio will be between 16 to one and 50 to one, typically designated as 16:1, 50:1 or somewhere in between. Essentially this means in a 16:1 chainsaw oil ratio, there will be 16 parts gasoline and one part oil.
To simplify the process, for a chainsaw oil ratio of 16:1 would require eight ounces of oil mixed with one gallon of unleaded gasoline. The majority of equipment designed for residential use will have a 50:1 chainsaw oil ratio, meaning 2.5 ounces of two-cycle oil for each gallon of gasoline.
Since outdoor equipment is designed to perform different tasks the amount of work it performs may make the chainsaw oil ratio unsafe for some other products. For example, an auger that operates with a two-cycle engine may recommend a ratio of 24:1 while weed eaters or blowers may be OK with a 50:1 ratio. Users should always verify the correct chainsaw oil ratio with the manufacturer before operating the equipment.
How Much Oil Is Not The Only Variable
While most people can read the user's manual or the instruction plate on the engine to find the chainsaw oil ratio, using the right oil is also important. Most two-cycle oil as a viscosity of 20W, but automotive oil should not be used in a two-cycle engine mix. There are specific additives in two-cycle oil that are not needed in a four-cycle lubrication system and hence are not present in that type of oil. This can cause the engine to quickly overheat and literally melt together on the inside.
Since chainsaws also require the use of chainsaw chain oil, care must be taken not to accidentally confuse the two. Although bar oil appears more like honey when it is poured and is generally a yellowish color where the engine oil will appear black and much thinner, if they are confused the engine probably will not run and the bar will quickly overheat and warp.
Regardless of the chainsaw oil ratio used in the equipment, when the saw will not be used for any length of time, the tank should be drained and the engine operated until all the fuel is out of the lines.