Cylinder Head Screws for YS Engine FZ110S YSF7309  [YSF7309]

Compatibility and fit notes for FZ110S

The YSF7309 screw set is intended as a replacement for YS Engine FZ110S series glow engines. These fasteners are supplied to reinstate the connection between the cylinder head and the engine housing on model glow powerplants.

Install this kit when routine inspection identifies worn, damaged, or missing head screws. Before fitting, examine threads and mating surfaces for damage or contamination. Begin screws by hand to guard against cross-threading, then tighten gradually in a crisscross order so the head seats evenly. Excessive torque risks damaging crankcase threads or distorting gasket faces.

Consistent head clamping preserves compression stability through thermal cycles and during spirited running. If vibration loosening has occurred, a removable thread locker may be used cautiously, but it should not be used to compensate for damaged threads or poor fit.