Stihl 3/8" 7 Tooth Rim Sprocket Kit - MS251, MS261, MS271

Modernize and restore the drive performance of your chainsaw with this Comprehensive Rim Sprocket Conversion Kit. This genuine replacement part and upgrade kit (1125 007 1002) is engineered to replace standard spur sprockets on a massive lineup of STIHL's most legendary farm, ranch, and professional saws. By upgrading to a floating rim system, the sprocket automatically slides along a splined hub to remain perfectly aligned with your guide bar groove, dramatically reducing friction, chain vibration, and premature wear.

This all-in-one kit provides a complete overhaul for your saw's clutch drive system. Optimized for a 3/8" pitch and a 7-tooth configuration, it delivers the industry-standard balance of fast chain speed and aggressive lugging torque for heavy-duty felling, bucking, and firewood cutting. Moving to a rim-style system simplifies your future maintenance—once this kit is installed, you can simply replace the worn rim component in the field instead of replacing the entire clutch drum assembly, saving you valuable time and money.

Fitment & Performance Note: This versatile kit is a direct factory replacement or conversion. It is the perfect maintenance choice to refresh aging classics like the 029 and 036, or to keep modern workhorses like the MS 271 and MS 291 running at peak efficiency with a professional drive setup.

What’s Included in the Kit

• Splined Clutch Drum: The heavy-duty foundation engineered to hold and support floating rim sprockets.
• 7-Tooth 3/8" Rim Sprocket: Provides precise, smooth engagement and consistent power transfer for standard 3/8" chains.
• Premium Components: Includes the essential factory-spec hardware required for a secure, direct-fit installation.

Technical Specifications & Fitment