YS Engine YSS1008 High-Precision Wrist Pin for 50ST/56SR Models  [YSS1008]

High-precision wrist pin for YS 50ST and 56SR

This wrist pin is an RC replacement intended for use with YS Engine models carrying the 50ST and 56SR service identifiers. It performs the critical role between piston and connecting rod, forming the pivot point that enables piston movement inside the cylinder.

Use this pin during rebuilds or maintenance when the factory part shows scoring, wear, or excessive play. Because this is a moving engine component, inspect the piston small end and rod bores for deterioration before installing and follow the engine's disassembly instructions closely.

Installation and tuning role

• Installation notes: remove the piston assembly per the manual, align the small end of the piston and rod, slide the wrist pin into place and secure with the specified retainer.
• Tuning role: a correctly fitted wrist pin preserves piston alignment and reduces play that can adversely affect compression and throttle response during tuning.
• Maintenance tip: routinely check for lateral play and surface damage when rebuilding; replace the pin at the first sign of wear to prevent accelerated damage to mating parts.