Carburettor Airbleed Screw OS25081202 for O.S. Engine 35RC 40SP 40P 50  [OS25081202]

Fine-tune low-throttle mixture with this airbleed screw

This component is an airbleed screw tailored for O.S. Engine 35RC, 40SP, 40P and 50 carburettors. It provides an adjustable bleed point that helps you dial in idle and first-throttle response while leaving the main needle assembly unchanged, useful when optimising performance for different running conditions.

Compatibility is limited to the engine model codes listed above. The part functions as a direct-replacement service item for nitro carburettor airbleed ports; confirm the replacement matches the bleed configuration of your carburettor prior to installation.

Installation is suitable for experienced hobbyists: remove the carburettor top or access cap, withdraw the old airbleed screw, and screw in the new unit until it seats. Make incremental adjustments and run the engine between changes to assess idle and throttle response improvements. Remember that this screw primarily affects low-throttle mixture rather than full-throttle settings.

Maintenance guidance: inspect and clean the screw and thread area to remove fuel deposits, check for any signs of wear on the seating surface or threads, and replace when necessary. Store spares in a clean container to prevent contamination.