50ST Needle Valve Replacement YSS1027S Compatible Part for RC Glow Engines by YS Engine  [YSS1027S]

Durability and Fit for YSS1027S

The YS Engine YSS1027S needle valve set is supplied as a service replacement for 50ST series glow engines, intended to restore correct fuel metering and extend service life. Use this set to replace degraded or damaged needles as part of preventative maintenance.

Needle valves control the fuel flow into the carburettor and are key to achieving stable idle and mid-range performance. Before installing the YSS1027S set, confirm the part number with your engine documentation and inspect O-rings, seats and the valve bore for wear or contamination.

Installation notes:

• Work in a dust-free area to keep the fuel circuit clean.
• Carefully remove the carburettor cap and note the old assembly's orientation, shims and spring positions.
• Install the replacement needle ensuring correct seating and unobstructed movement, then run a static check for fuel flow before refitting the engine to the model.