As happens with all “additional” parts, having a starter motor implies the having one more component that can undermine a kart’s efficiency and, therefore, must be kept under control. Its weakness, which causes the most problems, are the brushes, which are subject to particular wear after a considerable number of starts. In general, failure occurs in the filament of the brush and there is no way to predict this happening with any precision. However, it is possible to understand when wear starts to become excessive by paying attention to the warning signs.
For example, when the battery runs down much faster, as much as halving its autonomy.