B&D GT 6060.
several times motor runs full speed slows and gives low 'Pop' sound then stops. slight tap on paving it starts for 10 secs. then same, slows and a pop (like arcing), would this be a brush sticking? if not its new job as repairs no doubt would over ride the purchase price of £58. It's not switch that's ok. the action of tapping on paving I think must jolt the brush back on commutator. only a guess.
Just for record I know electrics don't take prisoners and work only in safe mode OFF, DISCONNECTED. Many thanks