idleskrue

An idleskrue, often spelled "idle screw," is a component found in the carburetor of many internal combustion engines, particularly older gasoline engines. Its primary function is to regulate the engine's idle speed, which is the rotational speed of the engine when it is not under load and the throttle is closed. The idleskrue achieves this by controlling the amount of air or air-fuel mixture that bypasses the throttle plate.

There are generally two types of idleskrues. One type directly adjusts the amount of air that bypasses the throttle plate, thereby influencing the idle speed. Turning this screw in typically increases the idle speed by allowing more air to enter the engine, while turning it out decreases the idle speed. Another type of idleskrue may adjust the position of the throttle linkage itself, indirectly affecting the idle speed.

Proper adjustment of the idleskrue is crucial for smooth engine operation. An idle speed that is too low can cause the engine to stall, especially when coming to a stop. Conversely, an idle speed that is too high can lead to increased fuel consumption, unnecessary wear on engine components, and difficulty in shifting gears in vehicles with manual transmissions. The correct idle speed is typically specified by the engine manufacturer and can be found in the vehicle's service manual.

Over time, carburetor components, including the idleskrue, can become dirty or worn, leading to unstable or incorrect idle speeds. Cleaning the carburetor and adjusting the idleskrue are common maintenance tasks for older vehicles. Modern vehicles primarily use electronic fuel injection systems, which manage idle speed through electronic controls, largely eliminating the need for a physical idleskrue.