A two-cycle internal combustion engine with rear compression chamber, other than that of a crank case. This present engine has valves that can be screwed on the engine block near top dead center, and is actuated by air pressure. This present two-cycle engine yet uses an oil sump similar to that of a four-cycle engine, which eliminating the need to premix oil with the fuel. This present engine has a stationary piston which operates within a movable piston to form a rear-compression chamber. The movable piston has ports near its crown to transfer charge to the combustion chamber. The movable piston also has ports near bottom of its skirt to allow the fuel and air mixture to enter the rear compression chamber. This engine has a piston seat which is adapted to connect the movable piston to the connecting rod.

A system and method for enhancing spark generation in an ignition coil of an internal combustion engine at low rotational speeds of the flywheel. The method and system monitor the rotational speed of the flywheel and, when the rotational speed of the flywheel is below a threshold rotational speed, the system and method supplies voltage pulses to the primary winding. The timing of the voltage pulses supplied to the primary winding are triggered off of voltage transitions in pulses induced in the primary winding upon rotation of the flywheel. Once the internal combustion engine has started, the switching device transitions into a second condition to disconnect the electrical storage device from the primary winding. The spark generation system of the present disclosure allows for starting of an internal combustion engine upon slower initial rotational speeds.

A system and method for enhancing spark generation in an ignition coil of an internal combustion engine at low rotational speeds of the flywheel. The method and system monitor the rotational speed of the flywheel and, when the rotational speed of the flywheel is below a threshold rotational speed, the system and method supplies voltage pulses to the primary winding. The timing of the voltage pulses supplied to the primary winding are triggered off of voltage transitions in pulses induced in the primary winding upon rotation of the flywheel. Once the internal combustion engine has started, the switching device transitions into a second condition to disconnect the electrical storage device from the primary winding. The spark generation system of the present disclosure allows for starting of an internal combustion engine upon slower initial rotational speeds.

A multiple-keyed crankshaft and flywheel provides for different ignition timing options for an internal combustion engine. The crankshaft of the engine includes multiple keyways set at designated angular displacements of the crankshaft that correspond with keyways on a flywheel for providing different timing options for the engine. The flywheel may be mounted to the crankshaft by aligning one of the keyways of the flywheel to one of the keyways of the crankshaft related to a particular ignition timing selection.

In an outside air intake duct, a duct body extends intersecting with a part of a vehicle body frame in a top view of a vehicle body. The vehicle body frame includes a duct holding portion. The duct holding portion is formed so as to surround the duct body at an intersecting site with the duct body. The duct body includes an air intake opening and a discharge port. The air intake opening projects outside the vehicle body frame. The discharge port is positioned inside the vehicle body frame. The duct holding portion includes a plurality of duct securing portions to secure the duct body. The duct securing portions are disposed so as to be positioned on both sides of the duct body nipping the duct body.

An ignition system of a combustion engine has a start-up adjustment curve with a maximum rotational speed, an operating adjustment curve and a switch-over device for switching between curves. The start-up adjustment curve is selected in the case of a start-up of the combustion engine. A rotational speed curve is divided into adjacent cycles. The start of the first cycle is the point in time of the second ignition after the start-up and the start of the subsequent cycles is in each case the point in time of ignition at which the rotational speed is less than in the case of the subsequent point in time of ignition. The criterion for switching to the operating adjustment curve is whether the average of the rotational speeds of successive cycles differs by less than a first tolerance value.

An ignition system of a combustion engine has a start-up adjustment curve with a maximum rotational speed, an operating adjustment curve and a switch-over device for switching between curves. The start-up adjustment curve is selected in the case of a start-up of the combustion engine. A rotational speed curve is divided into adjacent cycles. The start of the first cycle is the point in time of the second ignition after the start-up and the start of the subsequent cycles is in each case the point in time of ignition at which the rotational speed is less than in the case of the subsequent point in time of ignition. The criterion for switching to the operating adjustment curve is whether the average of the rotational speeds of successive cycles differs by less than a first tolerance value.

A multiple-keyed crankshaft and flywheel provides for different ignition timing options for an internal combustion engine. The crankshaft of the engine includes multiple keyways set at designated angular displacements of the crankshaft that correspond with keyways on a flywheel for providing different timing options for the engine. The flywheel may be mounted to the crankshaft by aligning one of the keyways of the flywheel to one of the keyways of the crankshaft related to a particular ignition timing selection.

A spark plug RFI suppression arrangement comprises a spark plug having a proximal end at which an ignition terminal is located and a distal end at which a pair of electrodes are separated by a spark gap. The spark plug further has an insulator portion and a conductive case located intermediate the proximal and distal ends. The arrangement further has an ignition wire having an end portion carrying a connector removably attached to the ignition terminal of the spark plug. A spark plug boot is located at the end portion of the ignition wire, the boot being configured to cover the connector and at least a portion of the spark plug. A radio frequency interference (RFI) suppression sleeve is connected to the spark plug boot and is in electrical communication with the conductive case of the spark plug such that interference produced by operation of the spark plug is suppressed by grounding through the conductive case.

A delayed ignition control device comprises a charging circuit and a delayed ignition control circuit. In the delayed ignition control circuit, the resistor R6 is connected between the positive electrode of the input end of the photo coupling IC and the initial end of the power coil N3; the shut-off switch S1 is connected between the negative electrode of the input terminal of the photo coupling IC and the ground; the collector electrode of the photo coupling IC is connected with the initial end of the power coil N3; the output end of the photo coupling IC is connected with the anode of the diode D5; the voltage holding capacitor C2 is connected between the negative electrode of the diode D5 and the ground; and the resistor R8 is connected with the negative electrode of the diode D5 and the controller electrode of the silicon controlled SCR2.