Insufficient filling of the carburetor with gasoline may be due to a malfunction of the fuel pump, as well as clogging or damage to the fuel lines.
To find the cause of the malfunction, disconnect the hose from the discharge pipe 1 (see fig. 2-79) and using the manual priming lever 8, check whether fuel is supplied. If there is no fuel, then disconnect the hose from the suction pipe 4 and check whether a vacuum is created at the inlet of this pipe. If there is a vacuum, then the fuel lines are damaged, and if not, then the fuel pump is faulty.
Additionally, the fuel pump can be checked at the stand. Rotating the drive roller with a frequency of 2000±40 min-1, check pump flow (must be at least 54 l/h at 20±5°С) and delivery pressure (should be 2.2-3.0 m of water. Art. at zero pump flow). If a malfunction is suspected, disassemble the pump and check its parts.