YS Engine YSF9156 Low-Speed Needle Valve for .91 .120SC .140 Glow Engines  [YSF9156]

Low-speed needle valve for glow engines

This RC-scale low-speed needle valve is intended as a direct replacement part for glow engine carburetors that accept the YSF9156 needle form factor. It addresses the low-throttle fuel metering circuit used during idle and light-throttle operation on compatible .91, .120SC and .140 glow engines.

Use this part when you need a service replacement or when fine low-speed mixture control is required during tuning. The valve’s role is purely in the carburetor low-speed circuit where small needle movements change idle mixture and transitional running; correct adjustment helps stabilise idle, reduce bogging at low throttle and improve throttle response in the low power band.

Installation is performed at the carburetor low-speed needle seat following the engine or carburetor manufacturer’s guidance, and tuning should be done incrementally while monitoring engine response. This item is an RC-scale accessory and is intended only for model glow engine use, not for any full-scale engines.