The starting transmission mechanism is composed of a driving gear, a one-way clutch and a fork. Its function is: when starting, the drive wheel and the flywheel gear ring are meshed with each other, and the starter torque is transmitted to the engine crankshaft. After starting, the drive gear and the flywheel gear ring are automatically disengaged to prevent the starter from overspeeding. Damage. The prone faults are: the drive gear is damaged, the one-way clutch is slipping and the shift fork comes out of the groove. 1. Elimination and prevention: 1. Replace the driving gear and one-way clutch that are compatible with them, and operate correctly. When replacing the new starter, polish the flywheel teeth and the starter drive teeth to a certain extent, and grind out the appropriate ones. The chamfer is used to facilitate the smooth meshing of the two teeth and to remove the debris on the front end of the starter and the terminals. When fixing the starter, it is necessary to install a spring washer to prevent the bolts from loosening, causing the drive teeth and the flywheel teeth to be out of concentricity and make an impact sound. 2. Restore the normal shift fork position and check the wear of the slip ring and shift fork. If the wear is too large, it should be processed to make it meet the standard matching requirements. 2. Failure analysis: 1. When the starter was changed, the meshing of the drive gear of the starter and the flywheel was not carefully checked and dealt with, so that the starting starvation could not be used normally, and it was caused by collision with the flywheel. 2. The slip ring and shift fork are worn out seriously, which makes the shift fork fall out when the starter is working and the drive gear cannot be completely returned.