
PROX Piston Ring Set - Ø78mm 4T (Manufacturer Ref: 02.6347): a set of rings designed for 4-stroke cross engines, intended for maintenance and top-end refurbishment.
PROX rings are machined from a specific alloy and calibrated to help reduce friction between the piston and the cylinder, thereby limiting wear and preserving gas sealing. Ideal during a piston refurbishment or preventive replacement, this set is aimed at riders performing top-end work on their cross machine.
Installation and practical advice: always replace the rings with a complete set and check the condition of the piston, cylinder, and ports before reassembly. Adhere to the specified clearance and manufacturer recommendations during the running-in period to ensure good sealing and regular piston operation.
Examples of compatible motorcycles (to be verified according to engine and size): GAS GAS MC 250 F FACTORY EDITION 2023, KTM 250 SX-F 2022, HUSQVARNA FC 250 2022. For any intervention, prioritise careful installation and appropriate tools to ensure the longevity of your top-end.