Crankshaft is not turned or swings and not making a complete revolution

The following possible causes to be investigated:

1. The pressure of starting air in starting cylinders is insufficient or the reducing valve on a pipeline of starting air is faulty. Pump up air to the required pressure, examine and adjust a reducing valve.
2. Excessive wear of piston rings. Check piston rings through scavenging ports (for the 2-stroke engine) or pull out random piston for inspection. Replace failed piston rings.
3. The main starting valve is jammed. Check and rectify.
4. Stuck in open position or leaky air starting valve(s). Check and replace faulty valves.
5. Jammed slide valves in the starting air distributor. Open and check the distributor internally. Replace faulty parts.
6. Starting air valve(s) seat is leaking. Check and lap the seating surface or replace gasket.
7. Incorrect valve opening/closing timings, incorrect tappet clearances, valves hang. Check and adjust as per maker's manual.
8. Pipelines from the starting air distributor of air are сhoked. Clean pipes
9. Indicator valves are open. Close indicator valves.
10. After docking, the packing gland of a stern tube is overtightened which the shaft from rotation. Adjust tightening as per Manual.
11. The propeller blocked, touches an obstruction or has a rope wrapped on it. Check and release the propeller from obstructions.
12. Starter cant reach deigned speed. Inspect starter, recharge batteries.