The average person will not care about the idling of the motorcycle, after all, it is idling, unless the engine is often turned off, otherwise it will not care. In fact, idling is very important, because idling too high and idling too low are bad. Idle adjustment screw has a great impact on the performance of the engine, the carburetor before the factory idle adjustment screw has been strictly tested and has been adjusted to the best position, so the user is generally prohibited to adjust the idle adjustment screw, after a long time of use, if the idle adjustment screw position does change and cause adverse consequences to adjust.

Motorcycle idling adjustment, the motorcycle will first move up, the throttle hand to the smallest position, then the engine in the case of no output power, can run at a stable lowest speed, and can continue to run for a certain time will not be turned off, this speed is called idle, adjust idle, is to adjust the idling of air and gasoline mixed ratio. Troubleshoot ignition system, carburetor, air filter and engine related mechanisms. Second, the carburetor can be adjusted only when the engine is in a hot state and the enrichment device stops working (the choke is reset or the enrichment valve is closed).

First, the concept of idle speed

Idle speed refers to the speed of the engine without power output. Because of the type and displacement of the car and have different values, the so-called engine idle is the lowest speed of the engine in neutral when the throttle valve is almost completely closed, in popular terms: idle is the working speed of the engine when the vehicle is parked and waiting.

A lot of friends who bought new cars. When buying a car, it can be seen that the business unboxes your car and then starts it, adjusting a small screw on the carburetor with a small screwdriver, which is to adjust the idle speed of your car, after patient running, the car after a few months or even 1 year of riding, you will find that the idle speed and the initial time has changed a little, which is to say the idling bad phenomenon, The main manifestations of poor idle speed are no idle speed of the engine, too high idle speed, idle speed instability and other three phenomena.

Second, motorcycle engine idling poor main performance

1. No idle speed

When the engine starts, the throttle handle can not be completely let go, otherwise it will stall, this phenomenon is called no idle engine.

The causes are: carburetor failure, or leakage between the carburetor and the cylinder, the cylinder pressure is too low.

Treatment method: According to the first easy after difficult, first simple after complex, from the principle of gradually check, adjust the throttle adjustment screw and idle speed adjustment screw, if the idle speed is not adjusted, it indicates that the carburetor is faulty, you can remove the carburetor, use 0.2mm fine wire through the holes, and use a high pressure gun to blow the channels and measuring holes; If there is still no idle speed, check whether the intake manifold bolt is tight, if loose, it should be tightened; If there is no idle speed, it indicates that the oil level of the carburetor float chamber is too low and should be adjusted. If the above methods can not be solved, you should check whether the cylinder pressure is appropriate (greater than 600 kpa), and check the sealing parts in turn, such as valves, pistons, and so on, and eliminate.

2, the engine idle speed is too high

The idling operation of the engine exceeds the specified range and cannot be lowered, or the phenomenon that the engine will stall when it is lowered is called excessive idle speed.

Cause: The throttle cannot return or the idle speed is too large.

Treatment: Check whether the throttle cable is flexible or whether the throttle spring is too soft, and replace it. Check whether the idle hole has become larger due to improper maintenance before, and replace it if it is larger.

3, the engine idle speed is unstable

When the engine is running at idle, the engine jitter, the speed is high and low, which is called idle instability.

Causes: ignition time is too early, the mixture is too thick or too thin, and the spark plug gap is too small.

Treatment method: rapid acceleration, if there is a "click, click" cylinder sound, it indicates that the ignition time is too early, should be based on the magneto rotor flywheel mark, adjust the timing and valve clearance; Slightly close the choke, if the rotation of the engine becomes worse at this time, it means that the mixture is too thin and the idle speed is unstable, at this time, it should check whether the oil level of the chemical oil float chamber is too low, and whether the idle oil channel is blocked, and remove it. If both of the above are normal, the gap between the spark plug electrodes should be checked to make it reach the standard value. After the motorcycle starts, the throttle handle can not be completely relaxed, otherwise it will stall, which is called the motorcycle no idle speed; If the idle speed is high and low, the speed is unstable, it is said that the idle speed is unstable.

When the general motorcycle leaves the factory, the idle speed has been adjusted. If there is poor idle speed, first of all, it should be repeatedly debugged according to the requirements of the manufacturer's instructions. If the poor idle speed cannot be solved after repeated debugging, there may be some of the following reasons:

1, the ignition time is not accurate, and the idle speed is poor in the idle state. At this time, the ignition time should be adjusted according to the regulations to make it accurate.

2, the engine has gas leakage phenomenon, at this time should check whether the carburetor and the engine connection is well sealed, spark plug and gas cap, crankcase and other sealing is good.

3, whether the spark plug works normally, whether the gap between the two poles is correct, adjust the gap between the poles, whether the idle hole of the carburetor itself is smooth and whether the air filter is smooth, it should be ensured that it is smooth.

Third, how to measure poor idle speed? Let's talk about normal idle

Rod ejector 125-150 displacement 1500+-100r/m

Small chain machine 125-150 displacement 1500+-200r/m

Pedal 1600+-100r/m

Generally speaking, the idle speed standard of 125mL displacement motorcycles is about 1450 RPM /min, and 500r/min is allowed according to the season, but many motorcycle friends like to reduce the idle speed to 900r/min. It is true that reducing the idle speed can save fuel to a certain extent, and in the hot car state, the idling speed is lower almost does not affect the vehicle. Little do you know, this practice will bring a lot of harm.

4. The harm of too low idle speed is:

1, because the idle speed is too low, the oil and gas mixing ratio is not ideal, the cold car is more difficult to start, usually pull the choke door to increase the mixture, and the heating time is correspondingly longer;

2. Easy to stall when slowing down or stopping, which is especially inconvenient for beginners;

3, such as idle speed is too low, when the gear of the engine is more difficult to change, smoothness can not be guaranteed, easy to cause impact between the gears, wear greater.

4, insufficient power when accelerating, can not normally play the performance of the motorcycle;

5, (the biggest harm) Some riders arbitrarily adjust the idle speed to the lowest point the engine can tolerate. Doing so, however, is in fact extremely harmful!

Because the general motorcycle oil pump is directly driven by the crankshaft of the engine, this directly causes the speed of the oil pump to be too low, resulting in insufficient oil pressure, especially for riding vehicles, their camshaft and bearing between a certain size of oil pressure, in order to form a certain thickness of the oil film to ensure lubrication. So there are some cars that only run thousands of kilometers, the nose has a strange sound, open a look, the camshaft is already scarred.

Five, the idle speed is too low is not good, higher?

Experienced riders know that in the cold early morning car is to warm the machine, the colder the day, the longer it takes. So in order to speed up, the acute people will vigorously pull the accelerator, or temporarily adjust the idle speed. This is indeed much faster, but at this time, because the cylinder body is too cold and attached to the cylinder wall on the surface of some gasoline droplets dilute the cylinder wall of the oil, so that the piston and the cylinder wall formed between the oil film is thin, at the same time, too high speed and aggravate the friction. At the same time, it should be noted that the oil supply at idle is very thick, and the atomization of gasoline is very poor, which also promotes the formation of larger droplets. It's only a matter of time before you burn the oil.

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