YS Engine YSR6202 61H Sub Needle Valve for Glow Engine Carburettors  [YSR6202]

Sub needle valve: purpose and fitment

This YS Engine YSR6202 Sub Needle Valve 61H functions as a replacement component for glow-fuel model engine carburettors. It is the needle part that meters fuel flow and enables finer idle and partial-throttle adjustments while tuning.

The component is intended as a serviceable sub needle valve and should be treated as a routine spare for maintenance and tuning sessions. Replacing the sub needle can help isolate whether wear or contamination in the needle assembly is affecting mixture control.

Installation notes: open the carburettor following the engine maintenance instructions, extract the old needle with care to avoid debris entering the carburettor, and fit the new needle maintaining the original orientation and clearances. Carry out small adjustments and confirm engine response on the ground prior to full-power operation.

Maintenance advice: because the sub needle has a direct impact on mid-range and idle petrol delivery, adjust it together with the main needle and idle screw when refining throttle response; inspect the needle tip regularly for signs of wear or contamination.