Evaporative emissions control for carburetors

An evaporative emissions control system for controlling the emissions of fuel vapors from the carburetor of an internal combustion engine, comprising:

• (a) an evaporative emissions control valve adapted to be connected in the air intake path to a carburetor such that when the evaporative emissions control valve is opened air is allowed into the carburetor and when the evaporative emissions control valve is closed fuel vapor is prevented from escaping from the carburetor;
• (b) a dual-wound solenoid actuator connected to the evaporative emissions control valve and having a primary winding and an auxiliary winding responsive respectively to first and second control signals to open the evaporative emissions control valve, wherein the solenoid actuator opens the evaporative emissions control valve with a first force level when the first control signal is provided to the primary winding, the solenoid actuator opens the evaporative emissions control valve with a second force level when the first control signal is provided to the primary winding and the second control signal is provided to the auxiliary winding, and wherein the second force level is greater than the first force level;
• (c) an ignition switch connected to a battery and to the primary winding of the solenoid actuator to provide the first control signal to the primary winding whenever the ignition switch is turned on;
• (d) a starter switch connected to a battery and to the auxiliary winding of the solenoid actuator to provide the second control signal to the auxiliary winding when the starter switch is closed to energize the starter of the internal combustion engine;
• and
• (e) vacuum controlled switching means for providing a third control signal to the primary winding to hold open the evaporative emissions control valve whenever the vacuum draw generated by the engine in the carburetor is below a selected pressure level less than ambient pressure.

A method for controlling the emission of fuel vapors from the carburetor of an internal combustion engine, comprising the steps of:

• (a) attaching an evaporative emissions control valve to the carburetor such that when the evaporative emissions control valve is opened air is allowed into the carburetor and when the evaporative emissions control valve is closed fuel vapor is prevented from escaping from the carburetor;
• (b) opening the evaporative emissions control valve with a first force level when the engine is in a steady state running condition;
• (c) opening the evaporative emissions control valve with a second force level when the engine is being started, wherein the second force level is greater than the first force level;
• and
• (d) closing the evaporative emissions control valve when the engine is not in operation.

An evaporative emissions control valve for controlling the emission of fuel vapors from the carburetor of an internal combustion engine, comprising:

• (a) an evaporative emissions control valve having a valve shaft and adapted to be connected in the air intake path to the carburetor such that when the evaporative emissions control valve is open air is allowed into the carburetor and when the evaporative emissions control valve is closed fuel vapor is prevented from escaping from the carburetor;
• (b) an evaporative emissions control valve controller means connected to the valve shaft for opening the evaporative emissions control valve when the internal combustion engine is running and closing the evaporative emissions control valve when the internal combustion engine is not running;
• and
• (c) an aperture of a fuel bowl vent of the carburetor and a passage in the valve shaft adapted to be aligned with the aperture of the fuel bowl vent such that the fuel bowl vent aperture is closed by the valve shaft to prevent fuel vapor from escaping from the fuel bowl when the evaporative emissions control valve is closed and the fuel bowl vent aperture is opened by the passage in the valve shaft to allow air to enter the fuel bowl when the evaporative emissions control valve is opened.