My moped has lost a bit of oomph. It is a Peugeot SpeedFight 4 125CC. It is (was) a pocket rocket. It (did) get up to to 62mph without any trouble (and I am 100kg).
But, at the moment it is only getting to about 56mph... maybe 58mph downhill.
Pull away is not as nippy either. Feels a bit ummmm...