The first step is to start
When starting the excavator, pay attention to the sound of the starter motor. If you can hear a clear "click" sound, and the start-up is successful within 3 seconds, it indicates that the start-up performance is good (the circuit, motor and engine are normal ). There is an unkind situation. The owner of the original excavator knows that you are going to test the machine and fully charge the battery in advance. Of course, when you test the machine, the power is of course sufficient. The actual battery storage capacity is seriously insufficient, waiting for you After the excavator was transported back, it was discovered that the battery was defective and the excavator could not start.
If you hear a dull motor sound during startup, it feels like the motor is not moving, and it suddenly starts again after a few seconds. In this case, it is most likely that there is a problem with starting the motor. If you hear a crisp starter motor sound, but need to start it many times to succeed, it may be a problem with the fuel injection pump. If you are out of luck, you need to repair the fuel injection pump soon after you buy it back, at least one or two thousand The cost is as high as several thousand yuan.
The second step, overload operation test
First of all, you need to adjust the throttle of the excavator to the idle state to see the engine speed at idle. It should be noted here that some bosses selling excavators have adjusted the meter. The speed was originally 1100, but only 850 was displayed. Buyers thought it was okay. The way to deal with these unscrupulous traders can only rely on experience to determine the approximate speed of the engine by listening to the sound of the engine. )
If the displayed speed is normal (for example, Yuchai's YC60 excavator should be 850-950 at idle speed, the maximum cannot exceed 1050), operate the engine to perform various actions, see what the engine is, whether there is a state or action to stop Can't move at all, and then do a single action overload to see how much the engine speed decreases, or directly stall. Generally speaking, the overload is not allowed to stop when the action is overloaded (slow action can be allowed). If it is off, you can bargain.
If the action does not turn off when idling, pull the throttle to the highest position, and then do the action. This time, the overload is mainly based on the single action overload, and then the compound action overload to see the speed and exhaust conditions, such as the drop speed is greater than 10 %, It means that the machine is defective. If the exhaust smoke is severe when overloaded, it means that the engine power is insufficient to support the normal operation of the hydraulic pump. This is quite difficult to handle. Generally, the boss asks the operator to set the engine speed at The 75% -80% position of the maximum speed is mainly for fuel saving. If the highest speed is severe, the basic action will be very slow at this position.
