Barnett Scorpion Lockup Clutch For Harley 4-Speed Big Twin 1936-1984

Centrifugal Lockup Technology

The standout feature of this kit is the weighted pressure plate. At low RPMs, the clutch is held together by heavy-duty coil springs, providing a smooth and manageable lever pull—perfect for city riding. However, as the throttle opens and RPMs climb, centrifugal force causes the weighted arms to apply additional mechanical pressure to the clutch pack. The faster you go, the harder it grips, ensuring that 100% of your engine’s power reaches the rear wheel without a hint of slip.

Precision CNC-Machined Components

Every Scorpion clutch features a CNC-machined billet aluminum pressure plate and a high-strength steel hub. Unlike cast OEM parts, these components are perfectly balanced and held to incredibly tight tolerances. This eliminates the “clutch wobble” common in vintage 4-speeds, resulting in smoother engagement, easier neutral finding, and a significant reduction in primary vibration.

Superior Friction Material

The kit includes Barnett’s legendary Carbon Fiber friction plates and tempered steel drive plates. Carbon fiber is chosen for its incredible heat resistance and ability to operate flawlessly in both wet (oil bath) and dry (open primary) environments. This versatility makes the Scorpion Lockup the preferred choice for both traditional enclosed primaries and radical open-belt-drive customs.

Installation and Compatibility

Designed as a high-performance replacement for the stock 4-speed “Stud” type clutch:

• Fits: 1936–1984 Big Twin models (Knucklehead, Panhead, Shovelhead).
• Primary Types: Compatible with stock chain-drive primaries and most aftermarket belt-drive systems.
• Custom Tunable: Includes multiple sets of springs, allowing you to customize the lever feel to your specific preference.
• Note: Designed for use with the stock-style clutch basket or Barnett performance baskets.