YS Engine YSS1008 piston wrist pin for 50ST/56SR models  [YSS1008]

Piston wrist pin for YS 50ST/56SR

This wrist pin is an RC-scale replacement part intended for use with YS-branded engine models that include the 50ST and 56SR identifiers in their service parts list. It serves the mechanical role between piston and connecting rod, providing the axial pivot for piston motion inside the engine cylinder.

Use this part when performing routine engine maintenance or rebuilding a small-displacement RC engine where the original wrist pin shows wear, scoring, or increased clearance. Because this is a direct engine component, inspect mating bores and the piston small end for wear before fitment, and follow the engine maker’s disassembly procedure.

Installation and tuning role

• Installation notes: remove the piston assembly per your engine manual, align the piston small end and rod, slide the wrist pin into position and secure the retaining method used by the engine design.
• Tuning role: a correctly sized wrist pin preserves piston alignment and minimizes play that can affect compression stability and throttle response in RC-scale engines.
• Maintenance tip: check for lateral play and surface damage during rebuilds, replace the pin if any sign of wear is present to avoid accelerated piston or rod damage.