Datsun 1200 used an automatic choke starting in 1976 (or starting 1972 for USA)

Since the amount of choke needed depends on outside temperature, adjust the automatic choke each summer and winter as necessary. When adjusted correctly, the engine should start on the first crank, and be able to take off immediately and drive the car without "warming it up"

Remove the lid of the Air Cleaner to inspect the choke. Here is the normal view of choke with the engine cold (engine off): the choke is almost completely closed. If you pump the accelerator pedal once, the choke should close 100% for flawless engine starting



If you do not see this, then adjustment is necessary. The secret to easy and correct adjustment is to adjust when the engine is completely cold. Then warm engine up fully, and double-check that the choke has 100% opened up


To adjust the choke, first remove the air cleaner — it must be removed to gain access to the choke. While removing, note any vacuum lines removed. These must be reconnected or temporarily plugged before running the engine

Adjustment procedure and photos are in the tech section at Choke Adjustment


I'm updating the photos, so posting some here that have been on FailBucket. These are of a larger DCH from a Datsun L20B engine but otherwise work exactly the same as the A12 version. For that matter so do most carburetors. Weber DGV is adjusted the same way

Attach file:

---

  Push plate down and let it spring back 20121019_152253_DSC04289.jpg (89.20 KB)


  Choke only partially closed 20121019_152143_DSC04286.jpg (117.98 KB)


  Choke Completely Closed 20121019_152236_DSC04288.jpg (101.10 KB)


  Choke Heater bimetallic sping rotates when hot, allowing butterfly to open 20121019_153005_DSC04313.jpg (95.36 KB)


  New Center Mark 20121019_153216_DSC04321.jpg (52.78 KB)


  Rotate the Mark past the tang when installing 20121019_153044_DSC04316.jpg (76.14 KB)