What is the purpose of carburetor limiter caps?

Carburetor limiter caps are specifically designed to prevent unauthorized adjustments to the carburetor settings. These caps restrict access to the adjustment screws, which control fuel-air mixture and idle speed settings. By limiting adjustments, manufacturers ensure that the engine operates within specified parameters, reducing the risk of improper tuning that could lead to performance issues, increased emissions, or engine damage. This is particularly important in applications where uniform performance and compliance with regulations are critical, such as in small engines used in lawn equipment or outdoor power tools. Limiter caps help maintain the integrity of the engine’s performance over time by ensuring that the settings remain consistent and within optimal ranges.