Motorcycle idle speed problem, how much idle speed is appropriate?

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.

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

Causes of motorcycle idling

First, the reasons for 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.

Second, there is no reason for idling.

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).

Third, the reasons for the 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.

References:

Baidu encyclopedia-idle speed