Q: When Cummins generator starting, can not rotate the crankshaft how to diagnose and repair?

A: When Cummins generator starting, starting system intact in case, if the transmission in neutral position, press the start switch, starter have sound but can not rotate the crankshaft, belongs to a mechanical failure. Cause and diagnosis and repair methods can not rotate the crankshaft of the engine as described below.

1、 Analysis of the reasons

① starter and flywheel teeth meshing bad. Ring gear and starter gear shock occurs when starting the engine, causing damage to the teeth or tooth-sided wear. If three or more consecutive teeth damaged or badly worn starter gear and ring gear teeth would be difficult to engage.

② stick cylinder. Parking stall when the engine temperature is too high, the heat is difficult to shed, piston rings and cylinder adhesion at elevated temperatures, unable to start after cooling.

③ crankshaft locking. Due to lack of oil lubrication system failure or cause sliding bearing friction, and eventually locking crank and not start.

④ fuel pump plug stuck.

2, Diagnosis and repair methods

① If there are three or more consecutive flywheel teeth damage, and with the starter gear just opposite, it will lead to the two gears can not be engaged. In this state, just use the crowbar to pry the flywheel turn at an angle, then press the start button you can start smoothly. For damaged flywheel teeth, generally can be welded repair.

Can be recognized from the flywheel starter ring gear installed ② loose when the mouth. If the ring is loose, shall be replaced with new parts. When installing, the first ring gear is heated in the heating tank, and then hot pressed to the flywheel, cooling can be fastened to the flywheel.

③ severe unilateral wear ring gear teeth, the ring can be depressed before turning the rear face, and then mounted on the flywheel to use.

④ The inspection gear properly, do not rotate the flywheel when starting, shall be deemed to internal engine failure, such as locking the crankshaft, pistons stick cylinders, clutch catching, etc., which should further observation. Can first check whether the damaged clutch catching, and then check whether the fuel pump plunger seizure and whether the foreign body inside the engine failure.