Carburetor Venting

Fuel vapors which might otherwise collect in carburetor bowl and pass directly into atmosphere are vented to carbon canister when engine is stopped. Flow of vapors is controlled by a fuel bowl vent valve or a fuel bowl thermal vent valve.

When engine is started, vapors will be drawn into engine for burning. The time at which vapors are drawn into engine will depend on operating mode of engine, when purging system is most efficient.