YS Engine 61ST-H Regulator Valve Replacement YSS7137 for RC Use  [YSS7137]

Regulator Valve Details and Fitment Advice

This item is the YS Engine YSS7137 regulator valve, supplied as a direct replacement for the 61ST-H regulator valve assembly. The notes below outline the part's role in fuel management, routine maintenance points, and fitment checks to ensure correct operation.

The regulator governs fuel pressure and flow in glow/nitro RC engines, supporting a stable idle and consistent throttle reaction provided the carburetor and fuel delivery are otherwise properly set. Consider the valve as a consumable service part when rebuilding or diagnosing inconsistent engine behaviour.

Fitment guidance: confirm the replacement code matches the original, maintain a clean working environment to avoid contaminating the fuel circuit, and hand-tighten fittings to the recommended sequence and torque. Conduct a warm-up and idle check after installation to verify steady pressure and reliable throttle performance.

Service considerations: the regulator works alongside needle and carb adjustments; coordinate those settings after replacing the valve. Replace O-rings and seals if they show signs of wear to maintain correct sealing and pressure.