Keep your compact chainsaw running smoothly with the STIHL 3/8" Picco™ 7-Tooth Rim Sprocket. This genuine replacement part (0000 642 1240) is engineered for saws equipped with the "Small" (SM) splined clutch drum system. Designed for the lightweight and precise 3/8" Picco™ (Extended Pitch) system, this rim sprocket ensures optimal power transfer for residential and light-professional tasks.
The floating rim design allows the sprocket to move along the splined hub, automatically aligning the chain with the guide bar groove. This self-aligning feature reduces lateral friction and heat, extending the life of your bar and chain. Whether you are maintaining a classic 017 or a modern MS 211, this rim sprocket provides a smoother cutting experience and lower vibration compared to standard spur sprockets. Because the rim is a separate component, you can replace it easily when worn without having to invest in a complete clutch drum assembly.
Fitment Note: This sprocket is specifically for 3/8" Picco™ (PM, PM3, PS) chains. It features the Small (SM) spline center hole, common on STIHL's homeowner and compact professional series.
Key Features & Benefits
- Precision Alignment: Floating rim technology keeps the chain perfectly centered in the bar track for smoother operation.
- Reduced Maintenance Costs: Replace just the rim instead of the entire clutch drum when the drive teeth show wear.
- Optimized for Picco™ Systems: Specifically designed for the narrow-kerf 3/8" P system for clean, efficient cuts.
- Small Spline (SM) Fitment: Compatible with a wide range of STIHL's most popular compact and mid-size saws.
- Hardened Steel Construction: Manufactured to STIHL’s rigorous standards for maximum wear resistance.
Technical Specifications & Fitment
| Manufacturer Part Number | 0000 642 1240 |
| Chain Pitch | 3/8" Picco™ (P) |
| Spline Size | Small (SM) |
| Tooth Count | 7-Tooth |
| Fits Professional Models | MS 170/171, MS 180, MS 191T, MS 210/211, MS 251 |
| Fits Classic Models | 017, 018, 019, 021, 023, 025 |
