125 motorcycle idling is unstable and easy to stall.

According to the above analysis, 1 mixture is improperly adjusted, too thin or too rich, so it is suggested to clean the carburetor, adjust it as follows, start the engine, and adjust the idle screw (iron screw) to make it rotate around 1500 rpm, 2. Adjust the mixture screw (copper screw) and screw it in slowly. At this time, the engine should respond. Don't screw too much at a time. It is advisable to twist it for a fifth turn first, and then stop it until the engine makes a uniform and powerful exhaust sound. At this time, the engine speed should be significantly improved. Then adjust the idle screw to make it work at the lowest stable speed. 3. The commissioning machine suddenly increased the throttle and quickly returned to the end. Air leakage in the intake part or crankshaft oil seal, suggestion; Check the crankshaft oil seal and replace it if it is damaged. 5. The gasket or screw at the carburetor joint is not tightly sealed, resulting in too thin mixture. To sum up, your car is more likely to have too thin carburetor, and it is less likely to have mechanical and air leakage (attention! ! ! ! Mixing and idling are two different things, don't mix them together. Give it a try and see if you can solve your problem!