market dynamics
What caused the idling of the motorcycle? What harm will it do?
Release date:2019.11.01

The cause of the idling of the motorcycle

1. Reasons for excessive idling

Carburetor throttle tension spring is weak, can not completely close the throttle;

(2) throttle loose or throttle cable in the jacket is stuck;

(3) reed valve or crankcase leakage;

(4) idle speed hole is too large.


2. No idle speed

(1) carburetor idle speed adjustment is improper;

(2) idle speed hole, idle oil channel, airway blockage;

(3) carburetor float chamber oil level is too low;

(4) reed valve or crankcase leakage (this fault is more in the two-stroke motorcycle).

Third, the reasons for the unstable idle speed

(1) ignition time too early;

(2) combustible mixture is too thick;

(3) air filter plug;

(4) spark plug gap is too small.

Symptoms of idling and troubleshooting

Its fault performance is: in the driving after increasing the throttle speed is slow, climbing a hill when weak, serious climb not uphill.

Its troubleshooting method

1. Fuel octane number is too low (replace qualified fuel);

2. The performance of cylinder compression ratio is too low (adjust the valve clearance to make the compression ratio normal);

3. Overheat and overheat of engine (eliminate overheat fault);

4. Improper valve clearance (adjust valve clearance);

5. Carburetor does not work properly (adjust carburetor);

6. Air filter does not work well (clean air filter);

7. Incorrect ignition timing (adjust platinum gap);

8. The capacitor does not work well or is damaged (update the capacitor);

9. The cylinder is not sealed enough (excluding the reason of not sealing);

10. Blocked exhaust pipe (clean or replace exhaust pipe).

Hazards of low idling speed

1. As the idle speed is too low, the oil and gas mixing ratio is not ideal, the cold car start is more difficult, usually to pull the choke and concentrated mixture, the warm time is also relatively long;

2. It is easy to turn off when slowing down or stopping, especially inconvenient for beginners;

3. If the idle speed is too low, it will be difficult for the gears of the engine to cooperate when the gear is changed.

4. Lack of power during acceleration, unable to give full play to the performance of the motorcycle;

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

6. The power cannot be linearly output due to insufficient speed of urgent refueling in the low-speed zone.

The handling method of idle speed of motorcycle

No idle

After the engine starts, the throttle turns to turn off after the complete release, known as the engine no idle speed. The reason is firstly the fault of carburetor and secondly the leakage of intake system. Oil and gas roads are mainly considered in judgment.

Adjust the throttle adjusting screw and the air adjusting screw. If there is still no idle speed, remove and open the carburetor, dredge the idle speed measuring hole and the idle speed airway with a steel wire less than 0.4mm in diameter, and then blow each hole clean with a pump. If there is still no idle after loading and testing, the carburetor float chamber oil level is too low or the reed valve, crankcase leakage should be considered. Start the engine for inspection. If the choke is closed and the idle speed is good, it indicates that the oil level in the float chamber is too low. The Angle of the float arm and tongue should be adjusted to raise the oil level. When the choke is closed, there is no idle speed, indicating that there is air leakage.

Excessive idling

Excessive idling speed means that the idling speed exceeds the specified range. For example, the maximum speed of light magnolia engine is 6000r/min, and the idling speed should be around 1300r/min. If the idling speed exceeds 1300r/min, it is considered too high. Idle speed is too high, not only affect the driver operation, but also fuel consumption will increase, accelerate the damage of transmission parts.

First check whether the throttle can be completely closed, that is, pull the throttle can be further closed, idle speed can also be reduced. Check whether the spring and throttle cable work properly, whether the throttle is loose, adjust or replace the new parts in time. In addition, timely check whether there is leakage phenomenon.

A condition of erratic idling

Idle running, the engine jitter, speed uneven, this phenomenon is called idle instability.

Engine idling instability can be used to speed up the throttle method for inspection, if there is a sudden explosion, ignition time is too early, should be adjusted appropriately late. Check again whether the oil level in the float chamber is too high, and whether the air filter is blocked, which cannot cause excessive concentration of combustible mixture.