GGT10 Carburettor Nipple Fitting (O.S. Engine OS4A407030)  [OS4A407030]

Fuel delivery nipple for O.S. carburettors

This O.S. Engine nipple is an aftermarket replacement intended for O.S. carburettor assemblies, aimed at restoring consistent fuel flow and sealing during tuning sessions. The guidance below covers fitment, flow checks, and how the nipple affects jetting and response on nitro-powered models.

During service, verify the nipple for obstructions, wear, and intact threads. Technicians often replace nipples when fuel delivery is erratic or when conducting a full carb strip and rebuild. Maintain cleanliness to prevent debris from entering the carburettor.

To install, clean mating faces, hand-thread to avoid cross-threading, and tighten just enough to seal without deforming the carburettor. Follow installation with a static fuel test and a controlled bench tuning pass before reinstallation in the model.

For tuning, a blocked or worn nipple can change fuel flow rates and affect mixture settings; replacing it can return predictable response. Always fit parts designed for O.S. carburettors to ensure correct sealing and thread engagement.