High-performance gravity-cast replacement top-end piston kit engineered to restore compression and crisp throttle response across modern Austrian mini-motocross platforms, matched to a Size B cylinder bore tolerance. Manufactured from a high-silicone aluminum alloy with a friction-reducing Molybdenum Disulphide skirt coating for a faster break-in and extended component life.
Specs & Details
- Manufacturer Part Number: 175-22991B
- Brand Number: 22991B
- Component Type: Cast Replica Top End Piston Kit (Includes piston, rings, wrist pin, circlips, gaskets, and wrist pin bearing)
- Size / Bore: Size B (51.96 mm)
- Material & Construction: Gravity-cast high-silicone aluminum alloy with T-5 heat treatment and MoS2 skirt coating
Two-Stroke Vehicle Fitment
| Make | Model | Engine Type | Year Range |
| Gas-Gas | MC 85 (17/14 & 19/16) | Two-Stroke Mini Motocross | 2021–2025 |
| Husqvarna | TC 85 / TC 65 | Two-Stroke Mini Motocross | 2014–2025 |
| KTM | 85 / 105 SX, XC, SXS | Two-Stroke Mini Motocross | 2003–2025 |
TSO Garage Note
An essential all-in-one top-end refresh kit covering a massive range of popular youth displacement platforms from the Pierer Mobility group, specifically sized to factory Size B cylinder tolerances. Having matching gaskets, bearings, and a precision-coated piston packaged together ensures proper clearance and reliable performance when servicing tired junior motors.
