One piston engine mechanism

Hi there,

I have been working on a project of analyzing (dynamic mechanism) the angular acceleration of a piston and crankshaft mechanism. I have kept the servo motor to 24000 deg/ sec constant in angular velocity, since I need it for 4000 rpm. I ran it with desired co-ordinates and axis, but I get a varying angular acceleration which is absurd. I don't understand where I am going wrong and would be really glad if someone can help me out in this regard! I have attached the files with this thread FYI. Kindly help me people! 🙂