YS Engine YSR6202 Sub Needle Valve 61H – RC Carburettor Spare  [YSR6202]

Understanding the sub needle valve and fitment

The YS Engine YSR6202 Sub Needle Valve 61H is supplied as a replacement part for glow-fuel model engine carburettors. It forms the needle element that meters fuel through the carburettor, enabling finer control of idle and part-throttle characteristics during setup.

As a sub needle valve, it should be viewed as a service item for routine maintenance or tuning. Swapping the sub needle is a useful diagnostic step to determine if needle wear or contamination is affecting the mixture.

Installation notes: remove the carburettor cover following the engine manufacturer's service procedure, extract the old sub needle carefully to prevent contamination, and seat the new needle in the same orientation and clearance as the original. Make small adjustments and verify behaviour with ground tests before returning to full-power running.

Servicing guidance: because the sub needle affects idle and mid-range fuel delivery, adjust it in combination with main needle and idle settings when optimising throttle response and inspect the needle tip regularly for wear or debris.