A lawn mower starter is used to start a lawnmower by turning a key. The traditional way of starting a lawn mower involves pulling a rope to turn the engine over. By mounting a battery and a lawn mower starter on a riding mower, the task of starting the engine becomes much less tiring. There are even upscale push mowers that utilize an electric lawn mower starter to fire the engine to life.
In the basic lawn mower starter design of many mowers, the mower's electrical charging system is also built-in. Not only does the lawn mower starter turn the engine over, but it also charges the battery. The wire brushes inside of the starter are designed to produce electrical current and send it to the battery as the engine runs. This can be accomplished in one of two ways: the lawn mower starter can be connected to the engine's flywheel by a gear or by a belt. The belt-driven lawn mower starter is the quietest in most cases, with the gear-driven unit being slightly noisier.
Lawn mowers use a small battery that can be easily stored in the restrictive space allotted in the mower's chassis. This use of a small battery reduces the available stored energy required to turn the engine over and start it. This mandates that the mower's starter be in peak condition in order to start the mower. Often a starter will begin to drag and spin slowly due, in part, to being subjected to severe engine heat.
Space restrictions force most starters to be mounted in close proximity to the engine's exhaust or inside of the body panels, all out of the flow of cool air. This heat can dry the lubricating grease from the starter as well as damage the wire wrapping inside of the starter, causing it to turn hard. The battery is forced to work harder in an attempt to turn the starter, causing a rapid loss in available battery power. Often what is thought to be a defective battery turns out to be a defective lawn mower starter.
Regular maintenance, including keeping dirt and dust cleaned from the starter and applying light oil to the starter shaft, will prevent premature failure. During off-season storage, starting the mower periodically is recommended. This keeps the starter from becoming stuck due to oxidation and gunk forming from a long period of non-use.