Handling method for abnormal pneumatic operation of outboard motor

During the normal use of the outboard motor, it is easy to have abnormal aerodynamics. So, once this phenomenon occurs, how should we deal with it? In this regard, outboard motor manufacturers say this:
First check the fuel level of the fuel tank. It is found that although the fuel level is not enough, it is still within the acceptable range. Unscrew the vent screw on the fuel tank cap to keep it unblocked. Use the soft air bag in the fuel hose to pump fuel into the carburetor. The emergency stop button of the boat engine is locked in the running position. The appearance of the two spark plugs has no carbon formation and is damaged. Adjust the position of the choke valve several times, and pull the ignition rope several times to discharge the air in the pipeline.
After the above attempts, it was still unable to start. It was initially suspected that the carburetor of the boat engine was blocked, so the carburetor was removed for inspection. After the carburetor was disassembled, it was found that the carburetor was not dirty, blocked, but a phenomenon attracted the attention of inspectors and engineers. The carburetor was full of lubricating oil, and the smell of gasoline could not be smelled. . Suspecting that there was something wrong with the fuel in the fuel tank, I used the soft air bag in the fuel hose to pump out part of the fuel in the fuel tank for inspection, and found that the fuel had no smell of gasoline, and the color was bright yellow like lubricating oil. .
Generally speaking, the fuel used in normal outboard motors is a mixture of gasoline and lubricating oil. The mixing ratio is gasoline: engine oil = 25:1 during the running-in period of the machine (10h). After the running-in period, that is, after 10h, the mixing ratio is Gasoline: engine oil = 50:1. After being asked by the inspectors, the crew on board did not know what kind of fuel the machine was using, let alone its mixing ratio, and some even added diesel to the fuel tank. Another point is that the crew is not clear about the function and use of the air release screw on the fuel tank cap. It is very likely that the air release screw has been unscrewed for a long time, causing the gasoline in the fuel tank to evaporate and only lubricating oil is left, causing the boat engine to fail to start.