YS Engine YSS1027S Precision Needle Valves for 50ST - Replacement Part for Model Engines  [YSS1027S]

Needle Valve Replacement for 50ST Engines

The YS Engine YSS1027S needle valve set is supplied as a replacement item for the 50ST series glow engines to restore proper fuel metering. It is intended to replace worn or damaged needles and support routine engine servicing for model applications.

Needle valves control the fuel feed into the carburettor and allow fine tuning of idle and mid-range mixture. Prior to fitting the YSS1027S set, confirm the part number with your engine documentation and inspect the valve seat, O-rings and surrounding bore for any signs of damage.

Installation notes:

• Carry out work on a clean bench to keep contaminants out of the fuel circuit.
• Remove the carburettor cap and carefully withdraw the old needle assembly, noting orientation and any washers or springs.
• Install the replacement needle set ensuring correct seating and smooth operation, then complete a static fuel flow check before returning the engine to service.