Abstract: An engine muffler is provided which comprises a first expansion chamber for exhaust gas which includes an exhaust gas inlet to be connected to an exhaust port of an engine, a second expansion chamber which includes an exhaust gas outlet, a first exhaust gas purifier in which a catalyst for purifying exhaust gas is coated on at least a concave surface of a concave base body which has a plurality of vent holes passing through the concave surface, the first exhaust gas purifier being disposed in the first expansion chamber such that the concave surface faces the exhaust gas inlet, and at least one second exhaust gas purifier in which a catalyst for purifying exhaust gas is coated on a base body including many pores, the second exhaust gas purifier being disposed between the first expansion chamber and the second expansion chamber. The engine muffler is obtained simply by improving a muffler used for a small-sized engine. The engine muffler has an extremely great effect of purifying exhaust gas.

Abstract: A four-cycle engine in which a mixed gas of a fuel and air containing a lubricating oil is transferred from a carburetor to a cylinder or a crank chamber, the gas is pushed out in the stage of descending the piston to the passage on the reverse side, transferred into a rocker arm chamber including an intake valve at the top of the cylinder via a passage including a valve gear mechanism, and it is directed to the cylinder in the intake stage, whereby the engine is lubricated by the lubricating oil. The engine has no oil pan and can be run at any inclination angle (360.degree.). Also disclosed is that it is also possible for the four-cycle engine to provide a diverged second passage extending to the crank room, to provide a lead valve on a portion of the second the passage, to provide a diverged third passage extending to the lower end of the crank chamber, to provide a lead valve or rotary valve, and to provide a fourth and/or fifth passage(s) to circulate the mixed gas.