LM2902: LM2902 output waveform distortion

Hi !

I want to use LM2902 to build a LPF circuit. The schematic diagram is shown as the following. Single Supply: 5V

My question is: whether I change the magnification or increase the amplitude of the input signal, the Vpp value of the output signal will be limited to under 2.5V. The waveform will distort when Vpp exceeds this value. When I try to remove C4, the circuit become a typical mu-circuit. But the above problems still exist. 

Thank you for your attention!