EN- 125 The motorcycle stops as soon as it releases the clutch. What happened?

Clean carburetor, check and adjust idle speed and mixture, and check for air leakage.

Motorcycle idle speed (commonly known as small fire) refers to a working condition in which the engine runs at idle speed when the motorcycle stops running. Idle speed directly affects the oil pumping capacity of motorcycles, and too high idle speed will also affect the fuel consumption of motorcycles.

operational approach

Simply put, it is to adjust the idle speed by adjusting the throttle opening. Open the left side plate of motorcycle and turn the idle speed adjusting screw clockwise to improve the idle speed, otherwise, reduce the idle speed; Generally speaking, the lowest stable idle speed is the best when the engine does not shake or stall.

In operation, the correct way is to adopt the method of "one high and one low" to adjust the idle speed. The so-called "one high" means that the engine speed should be increased as much as possible when adjusting the mixture adjusting screw (its purpose is to make the oil-gas ratio of the idle fuel supply system reach the best); "One low" means to reduce the engine speed as much as possible when adjusting the throttle screw (the purpose is to make the throttle opening smaller, thus reducing the fuel supply of the fuel supply system).

The specific adjustment method is as follows:

Step one, prepare. When the throttle knob is completely loosened, there should be a certain free clearance, an air filter should be installed, and the performance of other components should be confirmed to be good, and the oil products meet the standards. Then, start the engine to warm up and completely open the choke valve;

The second step is pre-adjustment. Adjust the throttle screw to ensure that the engine can run at a certain speed without stalling when the throttle knob is completely loosened;

The third step, a high. Adjust the air conditioning screw to increase the engine speed as much as possible;

The fourth step, one low. Adjust the throttle screw to reduce the engine speed as much as possible (125 displacement1400r/m; 100 displacement 1500 rpm). The adjustment parameters of mixed gas are not mechanical, even if it is the same batch and model, there will be differences. The screw of this car's mixture is screwed in to make it thinner, and drawn out to make it thicker. As long as the adjusted engine runs smoothly, starts smoothly, accelerates smoothly, and the fuel consumption is normal, the color of the spark plug can also help to judge whether the concentration of the mixture is appropriate. Under normal circumstances, the color of the spark plug should be brown. It is abnormal to be too black or too white, but the most common one is too black. You can ride like this for a few days to observe. If there is nothing unusual, you can use it like this without any adverse effects. Generally, the mixed gas screw of scooter is screwed to the end, and then pulled out twice. However, the performance of mopeds is quite different, which needs to be adjusted according to the actual situation, and so do other motorcycles.

Causes and symptoms of motorcycle idling instability

(1) Inappropriate ignition time, resulting in poor idle speed;

(2) the engine leaks air;

(3) The spark plug electrode gap is incorrect;

(4) The idle hole of carburetor is not smooth;

(5) Incorrect gasoline label (low octane number);

(6) The air filter muffler is blocked;

(7) The gasoline quality is not up to standard.

Show symptoms

Its fault performance is: after shifting gears during driving, the throttle increases slowly, and it is weak when going uphill, and it can't go uphill in serious cases.

Troubleshooting method: 1. The octane number of fuel is too low (replace qualified fuel); 2. The cylinder compression ratio performance is too low (adjust the valve clearance to make the compression ratio normal); 3. Engine overheating and overtemperature (troubleshooting overheating); 4. Improper valve clearance (adjusting valve clearance); 5. The carburetor is not working properly (adjust the carburetor); 6. The air filter is not working properly (clean the air filter); 7. The ignition timing is not allowed (adjust the platinum gap); 8. The capacitor is not working properly or damaged (update the capacitor); 9. The cylinder seal is not enough (excluding the reasons for not sealing); 10. The exhaust pipe is blocked (clean or replace the exhaust pipe).

Harm and treatment of motorcycle idling too low

1. Because the idle speed is too low, the oil-gas mixture ratio is not ideal, and it is difficult to start the cold car, it is usually necessary to drag the throttle to enrich the mixture, and the warm-up time is correspondingly long;

2. It is easy to stall when slowing down or parking, which is especially inconvenient for novices;

3. If the idle speed is too low, the gears of the engine will be difficult to match when shifting gears, and the ride comfort will not be guaranteed, which will easily lead to collision between gears and great wear;

4. More importantly, when accelerating, the power is insufficient, and the performance of the motorcycle cannot be played normally;

5. The biggest harm of low idle speed is that the oil pump can't work normally, which will lead to insufficient lubrication of internal parts of the engine, premature and excessive wear of parts.

6. The growth rate of emergency refueling in low-speed area is insufficient, and the power cannot be output linearly.

Treatment method of poor idle speed

abstract

Whether the engine runs well at idle speed is one of the signs to measure the engine performance. If the idle speed of the engine is too high, it will increase fuel consumption, increase the working temperature of the engine and accelerate wear. If the idle speed is too low, the oil pressure will decrease, which will affect the lubrication of various parts, aggravate the wear and increase the pollution to the environment. There are three main manifestations of poor engine idle speed: no idle speed, high idle speed and unstable idle speed.

No idle speed

After the engine is started, the engine stops after the throttle knob is completely loosened, which is called no idle speed of the engine. The first reason is carburetor failure, followed by air leakage in the air intake system. The oil and gas path is mainly considered in the judgment.

(1) Reasons for no idle speed

① Improper adjustment of carburetor idle speed;

② Idle metering hole, idle oil circuit and air circuit are blocked;

③ The oil level in the carburetor float chamber is too low;

④ The reed valve or crankcase leaks air (this fault mostly occurs in two-stroke motorcycles).

(2) Judgment and exclusion

Adjust the throttle adjusting screw and air adjusting screw. If there is still no idle speed, remove the carburetor and open it. Use a steel wire with a diameter less than 0.4mm to dredge the idle measuring hole and idle airway, and then blow all the holes clean with a pump. If there is still no idle speed after installation, it means that the oil level in the carburetor float chamber is too low or the reed valve and crankcase are leaking. Start the engine for inspection. If the choke valve is closed and the idle speed becomes better, it means that the oil level in the float chamber is too low, and the angle of the tongue of the float arm should be adjusted to achieve the purpose of raising the oil level. When there is still no idle speed after closing the choke valve, it means there is a leak.

Idle speed is too high

Excessive idle speed means that the idle speed exceeds the specified range. For example, the maximum speed of Qingqi Mulan engine is 6000r/min, and the idle speed should be about 1300r/min. If the idle speed exceeds 1300 rpm, it is considered too high. Excessive idle speed will not only affect the driver's operation, but also increase fuel consumption and accelerate the damage of transmission parts.

(1) Causes of high idle speed

(1) The throttle tension spring of carburetor is weak, so the throttle cannot be completely closed;

② The throttle valve is loose or the throttle valve cable is stuck in the sheath;

③ Reed valve or crankcase leaks;

④ The idle metering hole is too large.

(2) Judgment and exclusion

First, check whether the throttle can be completely closed, that is, pulling the throttle by hand can be further closed and the idle speed can be reduced. Check whether the spring and throttle cable work normally and whether the throttle is loose, and adjust or replace new parts in time. In addition, check whether there is air leakage in time.

Idle speed instability

When idling, the engine shakes and the speed is uneven, which is called idling instability.

(1) Causes of Unstable Idle Speed

① The ignition time is too early;

② The combustible mixture is too rich;

③ The air filter is blocked;

④ The spark plug gap is too small.

(2) Judgment and exclusion

Engine idling instability can be checked by quickly increasing the throttle. If there is a sudden popping sound and the ignition time is too early, it should be adjusted later. Then check whether the oil level in the float chamber is too high and whether the air filter is blocked. These conditions will not cause the combustible mixture to be too rich.