Abstract: The present invention is a tool free quick change spark plug mechanism. It includes a head insert, a spark plug and a locking housing. The head insert has a threaded base to be inserted into a spark plug port of an internal combustion engine. It is generally cylindrical and hollow, and has either a locking groove or an extended locking mechanism on its outside wall above the threaded base. The plug is generally cylindrical and elongated with an electrode for sparking and a terminal for a wire attachment, and has a seal with a greater diameter than the lower end of the plug for seating within the head insert. The locking housing is hollow and cylindrical to fit over the spark plug and head insert, and has on its inside wall, the other of the locking groove and extended locking mechanism.

Abstract: A new two-cycle internal combustion engine configuration and control strategy in which the unburned hydrocarbon emissions are measured in the exhaust manifold during the scavenging process using a fast response air fuel sensor. The signal from the sensor is used to control the operation of a low pressure ratio blower and the inlet fuel and oil flow. In this way the inlet flow of fuel and air may be reduced which controls the short circuiting loss of fuel during the scavenging process and reduces unburned hydrocarbons in the exhaust gas.

Abstract: In order to obtain good efficiency of a pulse combustion apparatus, an ignition plug is protected to extend its life span by way of controlling the rotation of the ground electrode at the wall face of a combustion chamber wherein 100.degree..about.200.degree. C. may be reduced from a conventional temperature of 900.degree. C. at the ground electrode in the ignition plug.