
PROX Cast Piston (manufacturer ref. 01.4121.A)
Designed for motocross, this PROX cast piston is a replacement part made from machined aluminium for 85 cm³ engines. With an oversize letter A and a precise diameter of Ø 48.45 mm, it adheres to the manufacturer's specifications for standard compression. Its domed head and specific machining for reed valves facilitate fitting onto the cylinder head, while the intake passage and two lubrication holes on the exhaust side skirt optimise localised lubrication without structural modification.
This part is intended for engines requiring an oversize A, and it integrates into maintenance or top-end rebuild operations. For a complete assembly, please ensure to have the accompanying parts: replacement rings 260068, pin 032021, clips CP1410C, needle cage 400406, and top-end gasket set 602087.