In cold weather, starting the engine often encounters various situations. In order to ensure the normal starting of the engine, I will give the following three suggestions.

1.Choose the right gasoline

Firstly, due to the difference in gasoline vapor pressure (RVP), the gasoline's evaporation (vaporization ability) will weaken in winter due to the low temperature. Therefore, low-vapor pressure gasoline (62KPa) should be supplied in summer, while high-vapor pressure gasoline (69KPa) should be supplied in winter. These winter gasoline can improve the engine's starting performance in winter.

Secondly, we should choose the regular gas stations (such as Sinopec and PetroChina) that supply winter gasoline, fresh 92# (or above) ethanol-free gasoline. The reason we don't use ethanol gasoline is that ethanol gasoline is easy to absorb water vapor from the air over time. In low temperatures, the water vapor will produce ice in the carburetor, causing the gasoline engine to fail to start.

2.Choose the right engine oil

In low temperatures, engine oil will become thick and unable to flow smoothly, and some may even stop flowing completely. The suitable ambient temperature for different oil brands is different. The average annual temperature in most areas of our country is between -18°C and 40°C. Generally speaking, for four-stroke air-cooled gasoline engines, choosing a well-known brand of winter and summer-universal oil 10W-30 (or 10W-40) with a grade of SF or above is enough. API grade (e.g. SJ) indicates the quality grade of engine oil. The "S" series represents gasoline engine oil, with specifications such as SA, SB, SC, SD, SE, SF, SG, SH, SJ, SL, SM, SN, etc. It is worth noting that gasoline engine oil and diesel engine oil cannot be mixed. The "C" series represents diesel engine oil. From "SA" to "SN", the later the letter, the higher the quality grade. Each increase in the letter means that the oil's performance is better than the previous one, with more additives used to protect the engine.

3.Proper operation

Close the choke and start the engine with the air intake closed. At low temperatures and before the engine starts, the fuel system cannot effectively vaporize the gasoline, and it is difficult to start the engine with the gasoline in liquid form. In this case, the choke helps by preventing some air from entering the cylinder to increase the gasoline-to-air mixture ratio and raise the engine speed to prevent the engine from stalling.

After the engine reaches normal operating temperature, restore the choke to its normal position. After starting, be sure to fully open the choke, otherwise, the engine may suffer from excessive air-fuel mixture ratio, incomplete combustion, black smoke, power loss, and carbon buildup. For engines with a starter motor, it is important to ensure that the battery is fully charged, as the battery's chemical activity decreases in low temperatures, and the flow of electrons is less active, resulting in a reduced actual discharge capacity. This will cause the starter battery to not provide enough voltage and power to start the engine. Therefore, it is easy to experience a dead battery at the time of starting. If you find that the battery is dead, you should charge it immediately or replace it with a new one.