In addition to the problems of the breadboard and the poorly made coil, why are you making the crappy FM transmitter anyway? Its performance is HORRIBLE!
1) It doesn't have a voltage regulator so its radio frequency changes as the battery voltage runs down.
2) It doesn't have pre-emphasis (treble boost) like all FM radio stations so the de-emphasis in all FM radios will make the sound muffled without high audio frequencies.
3) It doesn't have much power so its range might be as far (or as short) as you can talk loudly.