I found this DC brushed motor soft start circuit, As I suggested it uses a FET to open after a short period.
[url]http://www.electro-tech-online.com/elec ... start.html
Initially it passes a few amps thru the 0R5 resistor then as the cap charges and the gate on the FET allows the Fet to pass current, the electricity flows through the FET instead. So I think it's like a two stage on switch.
I built this up today out of curiosity, seemed to work but may need some tweeking. And I couldn't really put a consistent load on this crappy scooter without stalling the mortor.
Was a very simple circuit. I just used a FET I has out of an old upgraded controller.
Hope that helps.