Q: Cummins generator starting, the crankshaft can not turn how to diagnose and repair?
A: When Cummins generator starts, if the transmission is placed in neutral position with the starting system intact, press the start switch, if the starter has a loud sound and the crankshaft cannot rotate, it is a mechanical failure. Causes the engine crankshaft can not rotate the reasons and diagnosis and repair methods are described below.
1、Analysis of the causes
① Starter and flywheel teeth mesh poorly. Gear ring and starter gears in the engine will start the impact, resulting in tooth damage or tooth single-sided wear. If the teeth more than three consecutive damage or serious wear, the starter gear and the teeth of the ring will be difficult to engage.
② Sticky cylinder. Engine temperature is too high when the engine stops, heat is difficult to dissipate, high temperature piston ring and cylinder sticky, will cause after cooling can not start.
③ crankshaft sticking. Due to the lubrication function failure or lack of oil caused by the slide bearing dry friction, so that eventually hold the crankshaft and can not start.
④ Injection pump plunger stuck, can not work.
2、 Diagnosis and repair method
① If the flywheel has more than three consecutive teeth damage, and the starter teeth are exactly opposite, it will lead to the two gears can not be engaged. In this state, just use the pry bar to adjust the flywheel to an angle, and then press the start button to start smoothly. For the damaged flywheel teeth, generally can be repaired by welding.
② Loose gear ring can be confirmed from the flywheel case starter mounting port. If the gear ring is loose, it must be replaced with a new one. In the installation, the gear ring should be heated in the heating box first, and then pressed on the flywheel while it is hot, and then it can be fastened on the flywheel after cooling.
③ If the teeth of the gear ring are seriously worn on one side, the gear ring can be pressed down and the front and rear ends can be turned over and then installed on the flywheel.
④ After checking the gear mesh is normal, the flywheel does not rotate when starting, it should be regarded as an internal engine fault, such as crankshaft blocking, piston sticking cylinder, clutch stalling, etc., which should be further observed. Can first check the clutch is not broken stuck, and then check whether the injection pump plunger is stuck and the engine internal fault such as foreign objects.