O.S. Engine OS29781500 Carburettor Gasket GT55  [OS29781500]

Carburettor gasket purpose and fit

This OS29781500 GT55 carburettor gasket is an RC-scale replacement seal intended for use in carburettor assemblies. It performs the basic function of closing mating surfaces inside the carburettor to prevent air or fuel leaks that upset mixture and idle stability.

Intended use is maintenance and rebuild work on glow/nitro engine carburettors in model vehicles. The gasket is a small, service-level part that helps restore proper sealing when a carburettor is disassembled for cleaning, needle swapping, or minor tuning changes. Treat it as a consumable item when performing routine carb rebuilds.

Installation overview: remove the carburettor from the engine bay, disassemble only as far as required to access the mating faces, clean contact surfaces, replace the old gasket with the OS29781500 unit, and reassemble following original torque and alignment practices. After replacement, verify idle and throttle response on the bench before reinstalling into the model.

Tuning role: a sound seal reduces unmetered air which can mask needle settings or cause inconsistent running. If you have unstable idle or sudden lean/bog symptoms after a rebuild, double-check the gasket contact surfaces and seating as part of your diagnostic routine. Also inspect throttle shaft and mounting screws for air paths that mimic gasket failure.