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Adjustment of the carburetor on the moped "Alpha". How right?

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Adjustment of the carburetor on the moped "Alpha". How right?
Adjustment of the carburetor on the moped "Alpha". How right?

If one of the parts breaks down, the motorcycle will already work uncoordinated, intermittently or not work at all. Another thing is the setting. It may be needed after an accident, winter, or after a break-in. Adjusting the carburetor of the Alpha moped is often an almost mandatory item in maintenance, especially if the owner has identified problems with it. The fact that the motorcycle stalls, uses too much fuel, makes abnormal sounds, may mean that the carburetor needs to be adjusted. How to do this and how then to determine that everything is set correctly? First, it will not be superfluous to decide what processes are taking place there.

How does a carburetor work?

On the one hand, air enters, this is where the air filter is attached, and on the other, the cylinder, and the mixture comes out there. Below is the float chamber, jet and tube. As the piston moves down, it draws air from the air filter. The speed of this air is high enough that it causes a vacuum: the atmospheric pressure becomes greater, and due tothis, gasoline begins to flow from the float chamber through the jet and the emulsion tube. The fuel mixes with air and actually breaks down into dust. Moving on, it quietly flies into the cylinder. With this work, it may not be necessary to adjust the carburetor of the Alpha moped (110 or 72).

If the level of gasoline changes, it will pour out through the drain tube. This happens due to the overflow of the float chamber: floats, a shut-off needle with a rubber tip and a hole. When gasoline rises, the float blocks the flow of gasoline. Above is a mine, where a spool with a needle walks, and a cable stretches to it to the throttle handle. The needle enters the emulsion tube and jet. With gas, the space increases and the amount of mixture changes. This adjusts the mixture quality screw. The idle jet with the screw outward is designed for dosing the mixture. This is the second screw.

Mixture quality screw

What is the need?

In order to avoid too rapid wear of parts, it is important to choose the right mixture at idle, at full throttle and in the mode when the damper is not fully open. What should make the owner think about adjusting the carburetor of the Alfa moped in these modes? Violation of the ratio of air and gasoline. Ideally, it should correspond to 1:15, where there is only 1 part of gasoline. Signs of violation can be:

  • Difficulty starting engine.
  • Any idling instability - the sound of the engine running irregularly.
  • When turning the throttle knob all the way -no engine revs, slow acceleration.
  • Pop in carburetor or exhaust pipe.
  • The color of the candle is white or black.
Idle quantity screw

How to adjust the carburetor?

Before adjusting the carburetor of the Alfa moped, it must be started and warmed up. Tighten the screw for the quantity (idle) and quality of the mixture until it stops. The latter is necessary so that the engine does not stall. When the engine starts to stall, you should increase the speed with the travel speed screw. When the engine is ready to stall, you need to unscrew the quantity screw. Now the mixture quality screw is followed by the moment when the engine develops maximum speed. If too high - adjust the engine speed screw (idling screw). Then you need to spin until the engine stops gaining momentum.

Now at low RPM, the engine is able to run easily and not stall. Tighten the mixture quality screw until the engine starts to lose speed. The idle screw should be set to idle. The norm is approximately 1500-1200 rpm.

Check by looking at the candle

How to check the quality of the Alfa moped carburetor adjustment?

At this stage, you need to adjust the quality of the mixture on the go. To do this, you need to start a moped and go for a ride on half the twisted throttle. After that, you can look at the condition of the candle: black - too much gasoline while driving, white - air. How to be in this case? Can be pulled outneedle and grooves that regulate the amount of gasoline. When moving the retaining ring up, less fuel will be supplied, and more air, and vice versa. After that, the test is performed again, and if the engine does not stall when turned to full throttle, then this is a sign that everything is fine.

In addition, the problem may be in the main jet, which is responsible for the "full throttle" mode: in this case, it should be replaced with a smaller or larger one. The following actions will serve as a check: when driving at full throttle, you need to slow down a little. If pops are heard, then a smaller jet is needed.

Nagar on a candle


Regardless of whether the carburetor of the Alpha moped (72 or 110) needs to be adjusted, it is important to understand that it needs careful care. It is in this case that this beautiful and budget moped will last for years. If the motorcyclist plans to carry out maintenance on his own, then after an accident, a long winter or before running in, attention should be paid not only to valves, the integrity of the engine and brakes, but also to adjusting the carburetor of the Alpha moped.

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