Komatsu D31EX-21, Operation & Maintenance Manual, Page: 130 / 256

OPERATION
OPERATION
3-78
4. When the engine starts, release the key in starting switch
(2). The key will return automatically to the ON position.
5. Continue to run the engine at idling for 15 seconds after
starting.
During this time, do not operate the control levers or fuel
control lever.
6. After starting the engine, run at the engine at mid-range speed and travel slowly in forward and reverse to
equalize the temperature in all the equipment.