Primary Power Enrichment System

Purpose
Increases the air/fuel ratio during periods of heavy acceleration or high speed operation as necessary.

Operation
The power enrichment system, controlled by intake manifold vacuum, supplies extra fuel during these operating conditions.
- Manifold vacuum is applied to the power valve diaphragm from an opening in the carburetor base where it is connected by passages in the main body to the diaphragm.
- During idle and light load conditions, high manifold vacuum overcomes the force of the power valve spring and the valve is held closed.
- When the throttle opening is increased and intake manifold vacuum drops, the valve opens and fuel flows from the bowl through the power valve into the primary main well.