Patent ID: 8757121

Claim:
A method of controlling supply of supplementary fuel to a supplementary fuel supply passage in a carburetor for supplying a fuel and air mixture to an engine having a piston connected to a rotary crankshaft, comprising: providing an electromechanical valve in communication with and normally closing the supplemental fuel supply passage; providing an electronic control module sensing engine crankshaft rotation and determining the crankshaft rotary speed; providing a magneto device including a flywheel rotated by the crankshaft and having a magnet group, and a lamstack having at least a first leg carrying a first coil and a second leg carrying a second coil, with the magnet group and the lamstack first leg and first coil configured to produce a current for opening the electromagnetic valve created by the magnet group rotating past the lamstack first leg and the lamstack second leg and second coil configured to produce a current for powering the electronic control unit created by the magnet group rotating past the lamstack second leg; and the control unit controlling the supply of current to initially open the electromechanical valve only when the engine intake vacuum is at least about 80% of the peak engine intake vacuum, the engine crank angle is about 40° to 60° BTDC of the piston, the engine crankshaft speed is not greater than about 2,000 rpm, and the engine crankshaft has rotated not more than about 20 revolutions from initial cranking of the engine for starting the engine.