How do you know if the number 1 cylinder is on the compression stroke?

To determine if cylinder number 1 is on the compression stroke, you can perform a few checks: First, remove the spark plug from cylinder number 1 and put your finger over the spark plug hole while manually rotating the engine using a wrench on the crankshaft. If you feel air pressure pushing against your finger, the cylinder is on the compression stroke. Additionally, you can observe the timing marks on the crankshaft and camshaft; they should align according to the engine's specifications when cylinder number 1 is at the top dead center (TDC) on its compression stroke.