0174404 JOHNSON FLAME ARRESTER

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.
Note: The "EMERGENCY STOP" button will shut off both the fuel and the ignition.Do not start the engine if there is a "DO NOT OPERATE" tag or similar tag attached to the start switch or controls.Do not move any of the controls if there is a "DO NOT OPERATE" tag or similar tag attached to the start switch or 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
The engine control is set to the STOP mode and the gas shutoff valve does not close.
Unsuccessful successive attempts to start the engineUnburned gas may remain in the air inlet and exhaust system after several unsuccessful attempts to start the engine. The unburned gas may increase to a concentration that may ignite during a successive attempt to start the engine.Perform the following procedure to purge the unburned gas:
If the Cat Electronic Technician (ET) is not connected to the engine, connect Cat ET to the engine.
Verify that the value of the "Engine Purge Cycle" parameter is equal to 10 seconds less than the value of the "Crank Cycle" parameter.
Set the engine control to the START mode. The engine will crank for the "Engine Purge Cycle" time. Then, the gas shutoff valve will be energized and the ignition will be enabled. The engine will start.
Continue with your previous procedure.Automatic Starting
When the engine is in the AUTOMATIC mode, the engine can start at any moment. To avoid personal injury, always remain clear of the the engine when the engine is in the AUTOMATIC mode.
Manual Starting
Ensure that fuel is supplied to the engine. Ensure that no gas is leaking.
Ensure that the driven equipment is unloaded.
For generator set engines, open the main circuit breaker.
For industrial engines, unload the compressor or pump. Disengage the clutch (if equipped). Place the transmission and/or other attachments for the power take-off in NEUTRAL.
Illustration 1 g03791076
(1) Engine control "START" switch
(2) Engine control "STOP" switch
Verify that engine speed control on the OCP is set to an rpm that is appropriate.
Observe the "Configuration" screen on Cat Electronic Technician (ET) or on the OCP panel. Verify that the "FUEL QUALITY" and the "SPECIFIC GRAVITY" are correct.
The engine must be prelubed before the crankshaft is rotated. Damage can result if the crankshaft is rotated on dry bearing surfaces.
Note: The prelube oil pump will operate until the pressure switch is made for 30 seconds. The Electronic Control Module (ECM) will initiate the engine start-up after the prelube pressure switch detects 1 psi of oil pressure. If the module detects a signal for preventing the start-up, the corresponding diagnostic code will be generated.
Allow the engine to idle for 3 to 5 minutes.The engine speed should stabilize at low idle rpm. Perform these checks during the warmup:
Check all the pressure gauges.
Inspect the engine for leaks.
Listen for unusual noises.When all systems are normal, the rpm may be increased.Ensure that the oil pressure and the fuel pressure are in the normal ranges. After the engine has started and the warmup is complete, the engine can be operated at rated rpm and low load. The engine will reach normal operating temperature faster if the engine is operated at low rpm and with a low-power demand. This procedure is more effective than idling the engine with no load. The engine should reach normal operating temperature in a few minutes.