In order to initiate the operation of a combustion engine, the engine's components must be set into motion. This can be done in several different ways, but most modern all-terrain vehicles (ATVs) will feature an electric ATV starter. This device is essentially an electric motor that engages when power from a battery is sent to the unit, usually through the use of a key inserted into an ignition switch. When the ATV starter is engaged, it pushes a pinion against a flywheel gear within the engine that will essentially begin the engine's normal running processes.
The ATV starter is generally a small component, and its position within the ATV can vary depending on the unit's design and the manufacturer's specifications. It is usually concealed behind a body panel to protect it from impact damage, though this is not always the case. Very often the ATV starter motor itself is concealed within a steel casing or shell to protect more sensitive components such as brushes and wires. The steel casing will be bolted down somewhere on the ATV's structure to prevent it from moving; a wire will generally exit the casing at some point, and the wire is usually sheathed to prevent damage to the core.
Combustion engines run continuously by using the energy created by the firing cylinders, as well as the centrifugal force of the flywheels or gears within. When the engine is not in use, however, these components do not move, which means there is no stored energy to get the engine going. In the past, a hand crank was used to start the motion of the engine, and many motorcycles and ATVs use a kickstarter that accomplishes the same task. These can be difficult and inconvenient to use, however, so the electric starter was conceived. Both an electric ATV starter and a kickstarter are present on some ATVs in order to offer versatility for the rider.
The ATV starter is engaged when a user turns the ignition key. This sends an electric signal to the ATV starter motor, which in turn engages the components that will set the flywheel in motion within the engine. Once the flywheel is engaged, the motion of that wheel can set the combustion process in motion, thereby firing the engine and creating the energy for driving the ATV. The process generally only takes a second or more, and once the engine is going, it can sustain itself under its own power.