Engine does not start

Of course, you've checked the ignition system and made sure that all the hoses are on, in particular:

between intake air distributer and auxilliary air valve
between intake air distributer and declaration air valve
between crankcase breather valve and intake air distributer

and now you are ready to check the fuel injection, starting by pulling off the hose to the intake air distributer and checking the pressure in the main ring with a pressure gauge while starting, looking for the specified pressure of 2.5 kg/cm2 (35 psi).

pressure builds up
no pressure