How do you adjust the valve on 1990 B2000 pickup?

To adjust the valve on a 1990 Mazda B2000 pickup, first ensure the engine is cold. Remove the valve cover to access the rocker arms, then use a feeler gauge to measure the clearance between the rocker arm and the valve stem. Adjust the clearance by turning the adjusting nut on the rocker arm until the desired gap is achieved, typically around 0.008 inches for intake and 0.010 inches for exhaust valves. Reassemble the valve cover and ensure all components are securely fastened before starting the engine.