YS Engine FZ110S Wrist Pin YSF7329 Replacement  [YSF7329]

Piston wrist pin details and function

The YSF7329 wrist pin is a service replacement intended for YS FZ110S model glow engines. It provides the mechanical link between piston and connecting rod small end and is supplied for maintenance and engine rebuilds.

Inspect the piston and rod assembly for wear before fitting the new pin. Install with care to maintain smooth axial alignment of the piston in the cylinder, confirm retainers such as circlips are properly seated, and apply a light lubricant compatible with glow engines during initial running.

Because the wrist pin influences piston stability and ring sealing, replacing a worn pin can reduce lateral play and restore compression consistency, which supports predictable running without altering tuned adjustments.