Carter WD-0 531S Carburetor

Float level: 5/32″ – distance from float bowl cover, when needle is seated.
Gas line connection: 5/32″ Weatherhead nipple.
Idle adjustment screw – initial setting 1/2 to 1 1/2 turns open.
Unloader: 3/16″

Metering Rod jet 120-139
Metering Rod: 75-538 (standard), 75-539

Back out throttle lever adjusting screw so that throttle valves seat in bores of carburetor. With throttle valve seated, insert .015″ feeler gauge between anti-percolator stem and lips on anti-percolator arm. Bend lips so that center of indicator lines are just flush with top of anti-percolator plug. Care should be taken so there is an even adjustment made on both anti-percolator tips.

Unloader Adjustment

With the throttle wide open, distance between upper edge of choke valve and inner wall of air horn should be 3/16″. Adjustment can be made by bending tip on fast idle connector link.