Wiseco 868M05400 GP Series 2-Ring Piston for KTM 125 SX 2002-2011

Forged from high-silicon aluminum alloy for maximum strength and dependability.

Innovative forging design and piston skirt provide maximum horsepower and torque.

Wiseco High-Performance piston kits are priced with piston, rings, pins and circlips (unless noted otherwise).

Oversize pistons require cylinder sleeving.

Upgrade the performance and reliability of your KTM 125 SX with the Wiseco 868M05400 GP Series 2-Ring Piston. Designed for KTM 125 SX models from 2002 through 2011, this piston is engineered for high-performance two-stroke applications and dependable operation in demanding riding conditions. Its GP Series construction supports consistent power delivery, responsive throttle performance, and durable service when properly installed and matched to the engine setup.
The Wiseco 868M05400 uses a two-ring design to help maintain compression and support efficient combustion. Precision manufacturing helps promote a proper fit within the compatible cylinder, while the lightweight piston design contributes to responsive engine performance. This replacement piston is suited for motocross, off-road, and competition-focused applications where dependable internal engine components are essential.
Use the Wiseco part number 868M05400 when confirming compatibility with your KTM 125 SX and engine configuration. Professional installation is recommended, including inspection of the cylinder, piston clearance, ring grooves, wrist pin, circlips, and related components before assembly. Follow the motorcycle manufacturer’s service procedures and Wiseco installation guidelines to ensure correct break-in and long-term performance. Sold individually as one piston assembly.

Features:

• Brand: Wiseco

• Part Number: 868M05400

• Application: KTM 125 SX models from 2002-2011

• Series: GP Series

• Ring Configuration: Two-ring piston design

• Engine Type: Two-stroke performance application

• Quantity: One piston assembly