Try changing the ratio of the capacitors like in this FM transmitter:

 

Sorry to reply to the old thread, but thought it might be useful for anyone browsing the forum as I was. I built up a circuit modeled on this and annotated it here:

http://41j.com/blog/2014/12/npn-common-collector-colpitts-oscillator-notes/

I still don't fully understand how the tank circuit operates, I think I need to understand the capacitive divider better. Anyway, I figured the notes might be of use to someone.

 

Sorry to reply to the old thread, but thought it might be useful for anyone browsing the forum as I was. I built up a circuit modeled on this and annotated it here:

http://41j.com/blog/2014/12/npn-common-collector-colpitts-oscillator-notes/

I still don't fully understand how the tank circuit operates, I think I need to understand the capacitive divider better. Anyway, I figured the notes might be of use to someone.

If you start your own thread there is more likelihood of obtaining sympathetic responses. Raising an old thread from the dead is frowned upon.
The capacitive divider in the arrangement shown, in conjunction with the resonant inductor, has to provide voltage "gain" to overcome the less-than-unity gain of the common collector topology. It also provides a means of reducing the loading effect of the low valued emitter resistor on the tank.