O.S. Engines O-Ring(S-3) 27881820

The O.S. Engines O-Ring (S-3), part # 27881820 is a genuine OEM replacement seal used in compatible O.S. nitro engine carburetor applications.

This O-ring is commonly used around the mixture control valve or mid-speed needle area, where proper sealing is important for consistent fuel metering and reliable tuning. A worn, flattened, or damaged O-ring can contribute to air leaks, fuel seepage, unstable idle, or inconsistent needle response.

Replacing small sealing components during maintenance or rebuilds helps keep the carburetor properly sealed and the engine running consistently.

Key features

-Genuine O.S. Engines replacement part

-O-Ring (S-3)

-Part # 27881820

-Commonly used in mixture control / mid-speed needle applications

-Helps maintain proper carburetor sealing

-Supports consistent tuning and idle behavior

-Ideal for maintenance, rebuilds, and carburetor service

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