How many degrees of crankshaft rotation are required to complete a four stroke cycle in one cylinder?

• A. 360
• B. 720
• C. 180
• D. 540

Answer: (B)

In a four-stroke engine, each stroke (intake, compression, power, exhaust) takes 180 degrees of crankshaft rotation. Four strokes x 180 degrees each equals 720 degrees. That means a full cycle for one cylinder requires two complete crankshaft revolutions (two full turns of 360 degrees each).

If you only rotate 360 degrees, you’ve completed only half the cycle (two strokes). 180 degrees is just one stroke, and 540 degrees is one and a half strokes—still not a complete four-stroke cycle.