4 Stroke Engine The workings of the machine four steps 4 engine components do not include: spark plug serves to memercikaan fire, close the valve serves to close the cylinder bore, piston serves to regulate the volume of the combustion chamber, serves to connect the connecting rod piston to the crankshaft, crankshaft to change the piston movement up and down (vertically) into motion play. our stroke engine is a machine which requires energy to produce a four-step process up and down the piston, the rotation twice as crutches, and one round of peace noken (camshaft). Four process is divided into cycles: STEP suction Suction steps: Aiming to enter the mist the air - fuel into the cylinder. As engine power produced depends on the amount of fuel burned during the combustion process. The process is; 1. Piston moves from top dead point (TDC) to Bottom Dead Point (TMB). 2. Inlet valve is open, the fuel into the cylinder 3. As Kruk rotates 180 degrees 4. As rotates 90 degrees noken 5. Negative