Description
If you’re serious about extracting more power from your Big Twin, displacement is king—and this S&S piston kit delivers exactly that. By bumping your 883cc or 1200cc engine to a full 1250cc, you’ll gain meaningful torque and horsepower without requiring a complete engine rebuild. These cast flat-topped pistons are engineered to work with stock heads or S&S performance alternatives, making this one of the most straightforward ways to wake up your motor.
Technical Specifications:
- Displacement: 1250cc
- Compression ratio: 10.3:1
- Piston design: Cast flat-top
- Bore diameter: 3-9/16″
- Engine compatibility: 1984–’99 HD Big Twins
- Cylinder fitment: Stock 1200cc cylinders
- Cylinder fitment: 1986–’2003 883cc cylinders
- Cylinder compatibility: 2004–’16 883cc not compatible
- Installation: Boring required
- Head recommendation: S&S CNC ported
- Manufacturer: S&S Cycle
- Part number: 106-5555







