YS Engine YSS1008 Direct-Fit Piston Wrist Pin for 50ST/56SR  [YSS1008]

Piston wrist pin designed for YS 50ST and 56SR engines

This wrist pin is an aftermarket replacement part intended for YS Engine models that include the 50ST and 56SR references in their parts lists. It connects the piston to the connecting rod and provides the axial pivot for piston travel within the engine cylinder.

Fit this component when performing scheduled maintenance or a full engine rebuild if the original wrist pin displays wear, scoring, or increased clearance. As with any internal engine component, inspect the piston small end and rod bores for wear and follow the manufacturer's disassembly guidance before installation.

Installation and tuning role

• Installation notes: remove the piston assembly per the service manual, align the piston small end and rod, slide in the wrist pin and secure using the engine's retaining method.
• Tuning role: maintaining correct pin size and fit helps keep piston alignment and reduces play that can affect compression and throttle response.
• Maintenance tip: during rebuilds check for lateral play and surface defects, and replace the wrist pin if you detect any wear to avoid further damage.