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

Aftermarket airbleed screw for nitro engines

This airbleed screw is manufactured to fit O.S. Engine models 35RC, 40SP, 40P and 50 and serves as an accessible bleed point for low-throttle mixture adjustment. It allows fine control of idle and initial throttle response without the need to modify the main needle assembly, which helps when setting up for different track or field conditions.

Compatibility is confined to the engine codes listed above. The item should be considered a direct-replacement service part for nitro carburettor bleed ports; always verify the replacement's dimensions and thread profile against your existing part before installation.

Fitting is uncomplicated for those accustomed to engine servicing: remove the carburettor cap as required, extract the old airbleed screw and install the new one until it seats. Adjust in small increments and verify throttle and idle behaviour between turns, because the airbleed primarily affects the low-throttle mixture.

For long-term reliability, clean fuel deposits from the screw and surrounding area, inspect the threads periodically, and avoid overtightening which can damage threads or seating surfaces. Keep spare parts stored cleanly to prevent contamination.