Once turning switch on. When pressing foot switch to turn on starter, the starter sound of turning over sounds sluggish and the hotter the engine the harder it seams to turn. I have put a starter heat insulator sheet between the starter motor and the engine wrapping the starter motor. I have a 6 volt system and it is a new starter motor, sounds as if it needs more amps if this helps my description of the problem. I look forward to any help on this, thank you.