Stens 2-Cycle Engine Oil 770-643, Twenty-four 6.4 oz. bottles

What It Is

Stens 770-643 is a pre-mixed 2-cycle engine oil (50:1 ratio) designed for air-cooled small engines that require TC-W3 or JASO FD-rated oil. It comes in a case of twenty-four 6.4 oz. bottles, each treating one gallon of gas—ideal for handheld lawn equipment like trimmers, blowers, and chainsaws.

Fitment & Compatibility

• Engine types: 2-cycle air-cooled engines from brands like Echo, Husqvarna, Stihl, Ryobi, and Poulan that specify TC-W3 or JASO FD oil at 50:1 mix ratio.
• What to check before buying:
  • Verify your equipment’s oil-to-fuel ratio (must be 50:1; do not use for 40:1 or 32:1 engines).
  • Confirm your engine requires TC-W3 or JASO FD certification (check owner’s manual or oil cap).
  • This is a direct replacement for OEM oils like Echo Power Blend, Husqvarna XP, or Stihl HP Ultra—no adapters or special tools needed.
• Not compatible: 4-cycle engines, diesel engines, or any equipment specifying non-TC-W3 oil.

Key Things to Know

• Quality: Meets TC-W3 and JASO FD standards, offering low smoke, good lubricity, and spark plug fouling prevention. Suitable for high-RPM use.
• Installation difficulty: Extremely easy—pour one 6.4 oz. bottle into one gallon of unleaded gasoline (87 octane minimum), shake, and use immediately. No measuring required.
• Common gotchas:
  • Do not mix with other oil types or ratios; discard leftover premix after 30 days if stored in an unsealed container.
  • Bottles are single-use; resealing is not recommended.
  • Not for marine or water-cooled engines (different oil spec).

Should You Buy It

Buy if you own multiple 2-cycle tools and want a consistent, no-measure mix that meets OEM specs at a lower cost per bottle than most dealer brands. Avoid if your engine requires a different ratio (e.g., 40:1) or if you prefer synthetic oil for extended storage.