Home Products News Contact Us
Home > Supports > Diesel Generators > Why The Crankshaft Can't Rotate When The Diesel Generator Set Start?

Why The Crankshaft Can't Rotate When The Diesel Generator Set Start?

Nov. 01, 2021

When the diesel generator set is started, if the starting system is intact, if the transmission is placed in the neutral position and the start switch is pressed, the starter makes a noise and the crankshaft cannot rotate, it is a mechanical failure. The reasons that cause the crankshaft of the diesel generator set engine to not rotate and the diagnosis and repair methods are as follows.


30 kva generator.jpg


Reasons for the crankshaft not rotating when the diesel generator set is started: The motor and the flywheel gear are not meshed properly, and the ring gear and the starter gear will collide when the engine is started, causing tooth damage or single-sided wear of the tooth. If more than three consecutive teeth are damaged or severely worn, it will be difficult for the starter gear to mesh with the ring gear teeth. The second cylinder is sticky. When the engine temperature is too high, the engine stops and the heat is difficult to dissipate. The piston ring adheres to the cylinder at high temperature and cannot be started after cooling. The three crankshafts are locked, and the sliding bearing is dry friction due to the failure of the lubrication system or lack of oil, so that the crankshaft is finally locked and cannot be started. The plunger of the four fuel injection pump is stuck.


Repair method of crankshaft not rotating when diesel generator set starts:


(1) If the flywheel has more than three consecutive teeth damaged and it is exactly opposite to the starter teeth, it will cause the two gears to fail to mesh. In this state, you only need to use a crowbar to rotate the flywheel at an angle, and then press the start button to start smoothly. For damaged flywheel teeth, welding can generally be used for repair.


(2) When the ring gear is loose, it can be confirmed from the starter installation port of the flywheel housing. If the ring gear is loose, it must be replaced with a new one. During installation, the gear ring should be heated in a heating box, and then pressed on the flywheel while it is hot, and then fastened to the flywheel after cooling.


(3) When the unilateral wear of the tooth of the ring gear is severe, the ring gear can be pressed down, the front and rear ends are turned over, and then installed on the flywheel for use.


(4) After checking that the gear meshing is normal and the flywheel does not rotate when starting, it should be regarded as an internal failure of the engine, such as locked crankshaft, piston sticking in the cylinder, clutch jam, etc., which should be further observed. Check whether the clutch is damaged and stuck first, and then check whether the plunger of the fuel injection pump is stuck and whether there are foreign bodies inside the engine and other faults.


Starlight Power was founded in 1974 and is one of the earliest manufacturers of generators and diesel generator sets in China. If you want get more information, please feel free to send email to sales@dieselgeneratortech.com we will pay highly attention on your question.

Contact Us

  • Add.: No. 10 Kechuang Road, High tech Zone, Nanning, Guangxi, China
  • Tel.: +86 771 5805 269
  • Fax: +86 771 5805 259
  • Cellphone: +86 134 8102 4441
                    +86 138 7819 8542
  • E-mail: sales@dieselgeneratortech.com
Follow Us

Copyright © Guangxi Dingbo Generator Set Manufacturing Co., Ltd. All Rights Reserved | Sitemap

Update cookies preferences
Contact Us