Why does my speedfight 1 LC electric starter clicks but doen't work?

Hi, I currently own a 1998 peugeot speedfight LC prost edition 50. I bought it second hand and the person i bought it off said it had just been fitted with a new starter motor and he claimed the electric start worked. In the advertisment he said the bike had been stood for a few weeks. I have recently bought a new battery so that isn't the problem. I pull the back brake and press the electric start button but all that appears to happen is a small clicking sound and my oil light comes on. If you know how to solve this problem all answers will be apreciated.

Thanks Craig(craig_richardson008@msn.com)