The ZMZ-402 engine power system includes:

fuel tank, two fuel lines, pump, fuel fine filter, carburetor with throttle and air damper actuators and air filter with housing

Fuel from the tank goes through the fuel line to the diaphragm pump.

Elements of the power supply system ZMZ-402

It is driven by a camshaft eccentric that acts on the pump drive lever.

A filter made of fine brass mesh is installed on the inlet fitting of the pump.

When the engine is not running, fuel is pumped into the carburetor using the manual pump drive lever.

There is a hole in the bottom of the pump body.

Leaking fuel from it indicates a leak in the diaphragm.

Further, the fuel passes through the fuel filter, which consists of a housing, a plastic sump cup and a filter element.

Then the fuel enters the K-151 carburetor.

Excess fuel is drained from the carburetor back to the tank through the drain (drain) fuel line.

Features of the K-151 carburetor, you can see in the article - Features of the K-151 carburetor

K-151 carburetor adjustment can be found in the article - K-151 carburetor adjustment