Idle & Mixture Adjustments (B30A Engine)

Adjustments should be made when air temperature is 60-80°F and must be made within eight minutes after cooling thermostat has opened. Check that oil in damper chambers is within 1/4" of the upper edge. If necessary, fill with Automatic Transmission Fluid, Type "A".

1. Connect tachometer and CO meter, run engine at 1500 RPM until thermostat opens. Adjust engine speed to 800 RPM, 700 RPM if equipped with automatic transmission.
   NOTE: Use a suitable carburetor synchronizer and balance air intake of each carburetor.
   Fig 1: Stromberg Carburetor Fast Idle Adjustment

   Courtesy of VOLVO CARS CORPORATION
2. Adjust idle trimming screws to obtain a CO reading of 2.5%. Adjust link rods. With control against its stop on manifold bracket, link rods should be adjusted until there is a clearance of about 0.004" between lever and flange of primary throttle spindle.
3. Adjust hot start valve so that valve control is against the carburetor lever with valve piston in upper position and throttle control at idle.