So, there are two kinds of Timing that take place in every engine. There’s camshaft and ignition.
The Cam manages, opening and closing of the valves. The Ignition manages, when the spark plug fires. These different actions need to be timed together, to make the engine work.
If the camshaft is off, your engine will either be running rough or not at all. If the ignition is the problem, it isn’t as easy to notice. Because, it has four cycles and more cylinders to hide issues.
For ignition timing to work at its best, the air/fuel mixture in each cylinder, must fire just as the piston reaches, top dead centre ( TDC ).
The engine timing synchronises the motion, of the crankshaft and the camshafts.