Craftsman Chainsaw Fuel Ratio You Should Actually Use
For most Craftsman chainsaw models with a 2-cycle engine, the fuel ratio is 40:1, which means 40 parts gasoline to 1 part 2-stroke oil. A practical example is 3.2 ounces of oil per 1 gallon of gasoline.
Fuel ratio basics
The reason this matters is simple: a chainsaw engine depends on oil mixed into the fuel to lubricate the piston, crankshaft, and bearings. Too little oil can accelerate wear and seizure, while too much oil can cause excess smoke, plug fouling, and carbon buildup. In other words, the oil mix is not a preference item; it is part of the engine's survival system.
Some older small engines used richer mixes such as 32:1 or even 16:1, but many modern Craftsman-branded saws are documented as using 40:1. A few discussions around rebadged Craftsman/Poulan variants have also mentioned 50:1 or 32:1 depending on the exact model, which is why the model tag or manual should always win over guesswork.
Mix chart
The table below shows the common 40:1 mix used by many Craftsman chainsaws. It is a quick reference for preparing fresh fuel safely and consistently.
| Gasoline | 2-stroke oil | Mix ratio |
|---|---|---|
| 1 gallon | 3.2 oz | 40:1 |
| 2 gallons | 6.4 oz | 40:1 |
| 2.5 gallons | 8.0 oz | 40:1 |
| 5 liters | 125 mL | 40:1 |
How to mix it
Use fresh unleaded gasoline in an approved fuel container, then add the measured amount of quality 2-cycle oil. Shake the container gently until the fuel looks evenly blended. Only then should you fill the saw's tank with the finished fuel mix.
- Check the model number on the saw or owner's manual.
- Confirm the required ratio, usually 40:1 for many Craftsman units.
- Add gasoline to an approved container.
- Measure and pour in the correct amount of 2-cycle oil.
- Close the container and shake it thoroughly.
- Pour the mixed fuel into the saw's tank.
What fuel to use
Most Craftsman chainsaws run best on unleaded gasoline with a minimum octane rating around 89 and low ethanol content, often no more than 10 percent ethanol. Ethanol can attract moisture, which is one reason old fuel becomes a common cause of hard starting and carburetor trouble. Fresh fuel is usually better than higher octane fuel that has been sitting around for months.
- Use fresh gasoline, not stale fuel.
- Choose high-quality 2-stroke oil made for air-cooled engines.
- Keep ethanol content low whenever possible.
- Store mixed fuel only for the period recommended by the oil or fuel stabilizer maker.
Why the ratio matters
A correct ratio protects the engine during high-RPM cutting, especially when the saw is under load in hardwood or storm cleanup work. In practical terms, the difference between a clean-running saw and an overheated one can come down to whether the engine oil content matches the manufacturer's spec. Many small-engine shops say fuel errors account for a large share of chainsaw complaints, especially after storage.
"When in doubt, trust the model tag first, not the internet rumor." That is the safest rule for any Craftsman two-stroke saw.
Common mistakes
One common mistake is assuming every Craftsman chainsaw uses the same ratio. Craftsman sold many saws built by different OEMs, so the exact specification can vary by model family and production year. Another mistake is eyeballing the oil amount instead of measuring it, which makes the ratio drift enough to affect performance.
People also often reuse old mixed fuel because it "looks fine," but old gasoline can degrade quickly and create starting issues. If a saw becomes hard to start, bogs under load, or smokes heavily, stale fuel is one of the first things to check before blaming the carburetor.
Model-specific note
If your Craftsman saw is an older rebadged unit, the factory recommendation may differ from the common 40:1 figure. Some older American-built small engines used 32:1, while many modern consumer saws moved toward leaner 40:1 or 50:1 setups to reduce smoke and emissions. The safest path is still to verify the exact model number, because the right answer is always the one printed for that engine family.
Quick answer
For many Craftsman chainsaws, the correct fuel ratio is 40:1, or 3.2 ounces of 2-stroke oil per gallon of gasoline. If your model's manual or engine label says otherwise, follow that specification instead.
Key concerns and solutions for Craftsman Chainsaw Fuel Ratio You Should Actually Use
Can I use 50:1 in a Craftsman chainsaw?
Only if your exact model specifically calls for 50:1. Using a leaner mix than the manufacturer recommends can reduce lubrication and increase wear.
Can I use pre-mixed fuel?
Yes, as long as the premix matches the ratio required by your saw and is designed for 2-stroke air-cooled engines. Premixed fuel is often convenient for occasional users because it reduces measuring errors.
What happens if I mix it wrong?
Too little oil can overheat or damage the engine, while too much oil can cause smoke, plug fouling, and carbon buildup. Small ratio errors may not fail immediately, but repeated use can shorten engine life.
Should I use ethanol-free gas?
Ethanol-free gas is often preferred when available because it stores better and reduces moisture-related problems. If ethanol-free fuel is not available, fresh E10 fuel is usually acceptable for many Craftsman saws if the manual allows it.