Push start

By pushing or letting the vehicle roll downhill then engaging the clutch at the appropriate speed the engine will turn over and start.

If a battery is of a sufficiently discharged state that it cannot provide the power to turn an automobile self starter then it may also not be possible to activate the injectors.

A modern gasoline engine contains an electronic ignition system which precisely times the electrical pulse to the spark plug.

The advantage of such a device is that it can deliver a full power electrical pulse to the spark plugs even when the alternator is turning very slowly (as in push starting a motor).

The outdated method of a mechanically timed ignition system is that it cannot deliver a full electrical pulse at very low engine revolutions per minute (RPM).

In the early 20th century, many motorcycles could only be push started; the 1908 Scott was distinguished by introducing a kick starter feature.