Answer:
A 4-stroke engine fires once every second rotation of the crankshaft (every fourth stroke of the piston).
Answer:
Every 4 strokes of the piston, or every 2 full rotations of the crankshaft.
Explanation:
The 4 strokes are most commonly known as Suck, Squeeze, Bang, and Blow (don't laugh, this is serious.) Suck (intake of fresh air and fuel) and squeeze (compressing the air/fuel mixture) are both parts of the first full rotation of the crankshaft, then bang (igniting the fuel and air mixture) and blow (expelling the exhaust gasses from the cylinder) are parts of the second full rotation of the crankshaft. Then this cycle repeats for as long as power is required, or until there is no more fuel to be mixed with the air, or there is no longer any ignition.
