Please choose the correct ending to complete the given sentence: Cars & Other Vehicles: [header] How to clean a small gas engine [title] Remove the spark plug by using a socket. [step] It's recommended to use a spark plug tester. [title] Remove the air filter cover on the engine.

Ending1: [step] These are usually called small-bay air filters (xcs). [title] Once you have removed the oil from the oil pan, you need to clean your engine. Ending2: [title] Remove the fuel tank from beneath the engine unit. [step] First remove the fuel tray (or tube inside the engine). Ending3: [step] This is usually held by two screws. Take the filter out and you should see about four screws that connect the air filter to the carburetor, remove those. Ending4: [step] A spark plug tester may come with your vehicle or if you're not sure, ask your mechanic. Read the instructions provided on the head of the socket a little at a time.

Answer format: ending1/ending2/ending3/ending4