FLOAT CIRCUIT
The float assembly is compact for extremerigidity assuring little or no change in float setting due to vibration or heat. The cellular nitrophyl float is impervious to denting under normal handling and is not susceptible to punctures, assuring a
constant buoyance factor. The float extends around the metering portion of the casting to produce the effect of twin floats, but is made as a single unit.
The bowl is vented to the inside of the air horn through a single pressed-in tube located in the main casting. Some models include an additional small outside vent hole located in the bowl cover.
These balanced or semi-balanced vents automatically compensate for increased air cleaner restrictions which might reduce fuel economy. An additional outside vent is provided for the fuel
bowl (at upper end of plunger shaft) during idle and engine off mode.
Under extreme heat conditions, fuel vapors may form in the fuel bowl. The purpose of this vent is to allow these vapors to escape to the atmosphere rather than enter the intake manifold through the inside bowl vent. This vent assures fast hot engine restarts and improved hot idle performance.
A vapor vent hole, drilled into the bore of the carburetor above the throttle valve aids in faster hot engine restarts. It prevents the accumulation of fuel vapors in the bore of the carburetor by
allowing them to escape to the atmosphere. Some later models use a mechanically operated bowl vent valve located internally in the
main casting above the fuel bowl. At curb idle, the pump linkage opens the valve to allow fuel vapor to exit to the vehicle's vapor storage system.
RBS Float Adjustment
FLOAT LEVEL
With carburetor inverted, bowl cover gasketremoved and float resting on seated needle, the
dimension (A) from the casting to the top of the
small "bump" at toe of float should be as
specified. A "scale" may be used for gauging. To
adjust, remove float from casting and bend float
bracket.
