This is more or less the circuit you should consider if you were designing a COLPITTS oscillator: -
- Note that R3 is needed else it won't have enough phase shift to generate an oscillation
- Note that the capacitors and the inductor used are not low impedances unsuitable for use with an op-amp
- Using 50 uH and 100 uF are to radically low in impedance to work with an op-amp
So, simulate this COLPITTS as shown and then move on to making it run at 10 kHz (as per your Hartley intention) by lowering inductance and capacitance by the same ratio. Then play around with different ratios of L and C and see where the limitations are.
Remember also that these circuits can take a short/medium period of time to begin oscillating so don't expect a sine wave at the instant you switch on. Neither should you expect anything bordering decent sine wave purity. More than likely the waveform will clip against the rails or look triangular in nature due to slew rate limitations in the op-amp. Most good sinewave oscillators measure the output amplitude and control the gain (R1 and R2) to keep the amplitude stable and avoid clipping.
Then transfer this to a HARTLEY design by using inductors in place of C1 and C2 and a capacitor in place of L.
Also note this regarding the use of the 741.