ENGINE AR 9Y9871 - Caterpillar

Engine exhaust contains products of combustion which may be harmful to your health. Always start and operate the engine in a well ventilated area and, if in an enclosed area, vent the exhaust to the outside.
For initial start-up of a new or rebuilt engine, and for start-up of an engine that has been serviced, make provision to shut the engine off should an overspeed occur. This may be accomplished by shutting off the fuel supply and/or the ignition to the engine.
Unburned gas in the air inlet and exhaust system may ignite when the engine is started. Personal injury and/or property damage may result.Before starting an engine that may contain unburned gas, purge the unburned gas from the air inlet and exhaust system. Refer to the topic on purging unburned gas in the "Starting the Engine" section.
Do not start the engine or move any of the controls if there is a "DO NOT OPERATE" warning tag or similar warning tag attached to the start switch or to the controls.Ensure that no one will be endangered before the engine is started and when the engine is started.Perform the procedures that are described in this Operation and Maintenance Manual, "Before Starting Engine" (Operation Section).Purging Unburned Gas
The following events cause unburned gas to remain in the air inlet and in the exhaust manifold:
Emergency stop
Engine overspeed
Unsuccessful successive attempts