What indicates when rotor flights need replaced? The front ones stick up quite aways from the mounting bracket. The rear are flush with the mountings and get sharp futher back. If the back are worn worse than the front, does the front ones need replaced also? If front round bar concave section is worn more than the middle and back, should they all be replace or just the worn one. Also, feed accelerator blades have been flipped over once, now both sides are worn half way through and come to a point at the top, should they be replaced?