Avoid blaming the starter right away when you face a starting circuit problem. Diagnose
Battery Cable clamps, cables, and condition of the battery. You should inspect the starter solenoid, starter mounting bolts, fuse box, ignition switch circuit, gear position switch or clutch start circuit, and starter cut relay. If the starter doesn't activate, you should test the fusing of the starting system and battery voltage at solenoid. In case of slow turnover by the crankshaft by the starter, you may want to test its turning voltage and current draw. When the starter receives power but fails to engage remove and examine the starter/solenoid assembly.