What should be done with the fuel valve before disassembling a small gas engine?

Before disassembling a small gas engine, it is essential to shut off the supply of fuel to prevent any accidental flows that could lead to spills or fires. Shutting off the fuel valve minimizes the risk of fuel leaking into the engine or surrounding areas, creating hazardous conditions during maintenance or repair work.

By pushing the fuel valve lever to the closed position, you ensure that fuel does not escape from the tank or lines, allowing for a safer disassembly process. This step also helps avoid contamination of the engine's interior components with fuel, which can lead to complications during repairs or maintenance.

Other choices suggest either opening the fuel valve, which would allow fuel to flow, or leaving it untouched, which does not take the necessary precautions to protect against potential hazards. Checking the fuel level is not a sufficient preventive measure on its own, as it doesn’t address the risk of fuel spillage during the disassembly process.