What do you primarily verify when inspecting valve springs to prevent valve float?

When inspecting valve springs to prevent valve float, the primary aspect to verify is the installed height. The installed height of a valve spring refers to the distance between the surface of the cylinder head and the spring seat when the spring is compressed and installed in the engine. This measurement is crucial because it directly influences the spring's ability to maintain sufficient pressure on the valve, ensuring proper closure and preventing the phenomenon known as valve float.

Valve float occurs when the spring cannot keep up with the rapid motion of the valve, typically at high RPMs. If the installed height is incorrect, it can lead to inadequate spring pressure, diminishing the spring's effectiveness in keeping the valve tightly closed during engine operation. By verifying that the installed height is within the manufacturer's specified range, technicians can ensure that the valve springs will function correctly, maintaining proper valve operation and preventing valve float.

While the other options might be relevant in certain contexts, such as ensuring the correct design or checking for wear, installed height is the most critical factor in preventing valve float.