YS Engine YSF1555 High-Speed Carburettor Needle Seat FZ - Upgrade Part  [YSF1555]

FZ high-speed seat overview

This YS Engine YSF1555 high-speed needle seat, FZ type, is a direct replacement intended to deliver steady high-rpm metering in RC glow engines. The FZ geometry interfaces with the high-speed needle and influences mixture at elevated engine speed.

Installation follows standard carburettor service steps: detach the bowl, remove the needle assembly, fit the new seat and reassemble. Watch for cross-threading and avoid introducing dirt during the procedure; careful alignment reduces the risk of binding.

The seat supports consistent needle adjustments and is thus important for repeatable top-end response, rather than acting as a tuning element on its own. Regular inspection and cleaning with suitable carburettor cleaner will help maintain reliable high-rpm behaviour.