FZ110S Head Fixing Screws YSF7309 by YS Engine  [YSF7309]

Tuning-focused head screw set for FZ110S

The YSF7309 screw kit is specified for the YS Engine FZ110S model range and replaces the original head fastening hardware. These fasteners restore the joint between the cylinder head and crankcase on glow engines used in models prepared for high-RPM operation.

Replace worn or missing screws during tune-ups or after competitive running. Verify that mating surfaces and threads are clean and intact before fitting. Hand-start screws, then tighten evenly in stages and follow a crisscross pattern to avoid uneven seating. Over-torquing can strip crankcase threads or warp gasket surfaces, so tightened control is essential.

Reliable head clamping contributes to repeatable compression and consistent running while tuning. If vibration loosening occurs during track work, a small amount of removable thread locker may be applied, but do not depend on it to correct damaged threads.