Datsun & Mazda
Open throttle and close choke. Release throttle lever first, to hold choke closed. Remove choke cover, and using rubber band, hold choke valve closed. Manually pull vacuum break diaphragm stem out fully (keep straight) in order to compress diaphragm. Measure clearance between choke valve and air horn wall. If adjustment is necessary, bend vacuum break connecting rod. See Fig 1.