76 280c solex 4a1 choke adj for cold start

[huffandpuff]

loosened up 3 8mm bolts on housing retaining cover . turned cover ccw to line up index maks tighten down screws started up the car few backfirwes thru carb when turing housing cover didn't see any movement in choke strangler clockwise to counterclockwise am I missing a step here to adjust bi metal spring with choke strangler ?? reset the index marks no more backfire but choke strangler isn't fully closed for cold start