Owner’s manual
Is 40 1 or 50 1 better for chainsaws?
For the Craftsman 358351820 gas chainsaw, 40:1 is the better choice because it is the manufacturer-recommended fuel mix. A 40:1 mix provides more 2-cycle oil for lubrication than 50:1, which helps protect the engine under load and during hot operation.
What to use for the Craftsman 358351820
The manual calls out Craftsman 40:1, 2-cycle engine oil (air cooled) and also notes using fresh fuel with the proper gasoline-to-oil ratio at the start of the season. Use the ratio in the 358351820 owner's manual.
Quick comparison
| Mix ratio | Oil per 1 gallon gas | Typical result |
|---|---|---|
| 40:1 | 3.2 oz | More lubrication, better protection for older 2-cycle designs |
| 50:1 | 2.6 oz | Less oil, can run cleaner, but offers less lubrication margin |
How to mix 40:1 correctly
- Use fresh, unleaded gasoline (avoid old fuel).
- Measure 3.2 fl oz of 2-cycle oil per 1 gallon of gas.
- Mix in an approved fuel container; shake to blend.
- Fill the tank and tighten the cap securely.
- If you suspect fuel delivery issues after a mix change, inspect the fuel line and fittings for cracks or leaks.
When 50:1 makes sense (and when it does not)
50:1 is common on some newer 2-cycle engines designed and tuned for that ratio. On the Craftsman 358351820, running 50:1 reduces lubrication compared to the specified 40:1, which increases wear risk over time.
Why it matters
The fuel-oil ratio directly affects engine lubrication, piston and ring life, and carburetor performance. Using the specified 40:1 mix helps the saw start easier, run more consistently, and last longer.
Last updated: January 2026
How to find chainsaw model number?
The model number for a Craftsman chainsaw is printed on the model and serial label attached to the saw body. On model 358351820, the label is typically on the motor housing or handle area; copy every digit exactly so we can match the correct parts and manual.
Where to look on a gas chainsaw
Check these common label locations first:
- Side of the engine/motor casing
- Near the rear handle or trigger area
- Under the top cover (near the air filter cover)
- Bottom of the saw body near the oil and fuel tanks
- Near the bar mounting area (clutch cover side)
What the model number looks like for this Craftsman
For this unit, the model is shown in the documentation as 358.351820 (often printed with a dot). When ordering parts, it is commonly entered without punctuation as 358351820.
| You see on label/manual | You enter for parts lookup | Why it matters |
|---|---|---|
| 358.351820 | 358351820 | Ensures the correct parts list and diagrams |
| Letters and numbers | Same characters, same order | One wrong character can pull the wrong carburetor, chain, or fuel line |
Tips to record it correctly
- Write the full model number and any serial number
- Take a clear photo before the label gets oily or scratched
- Avoid guessing missing digits; clean the label and re-check
- Use the model number (not bar length) to choose parts like a chain, clutch, or carburetor
Why it matters
Chainsaws often share similar-looking bars, chains, and engine parts across multiple versions. Using the exact model number helps us match the correct Craftsman parts breakdown, maintenance specs, and safety information in the 358351820 operator's manual.
Last updated: January 2026
What is the Craftsman 358351820 42 cc 2-cycle gas 18 chainsaw?
The Craftsman 358351820 is a gas-powered, 2-cycle chainsaw that uses an 18-inch guide bar and is designed for cutting limbs, firewood, and general property cleanup. Our model’s operator documentation identifies it as a 2.4 cu. in. (40cc) 2-cycle saw with an 18-inch bar.
Quick specs and what they mean
Here are the key identifiers you can use to confirm you have the right Craftsman chainsaw model and to shop the correct parts.
- Model number: 358351820
- Engine type: 2-cycle gasoline engine
- Displacement: 2.4 cu. in. (40cc)
- Bar length: 18 in.
- Fuel mix: 40:1 (3.2 oz 2-cycle oil per 1 gallon unleaded gas)
- Bar oil guidance: Fill bar oil tank whenever you fill the fuel tank
| Item | What to use | Notes |
|---|---|---|
| Fuel | Unleaded gasoline + synthetic 2-cycle air-cooled oil | Mix at 40:1 |
| Mix ratio | 3.2 oz oil per 1 gallon gas | Common “1 bottle per gallon” mix |
| Bar oil | Chainsaw bar oil (SAE 30 acceptable short-term) | Oil output is automatically metered |
Why it matters
Matching the correct Craftsman 358351820 model details helps you avoid wrong-fit parts (like the wrong chain or bar) and prevents common running issues caused by incorrect 2-cycle fuel mix or low bar-and-chain lubrication.
Helpful references for owners
- Use the 358351820 operator's manual for safety rules, operation, maintenance intervals, and the parts list.
- If your saw is difficult to start, follow the checks in tips for a hard to start chainsaw (fuel freshness, correct choke use, spark arrestor condition, and more).
Last updated: January 2026
