Abstract: Disclosed is a multi-cylinder engine having auxiliary valves in addition to intake and exhaust valves. A common exhaust gas passage is formed in the cylinder head and is connected to each of cylinders via the corresponding branches. Each of the auxiliary valves is arranged in a respective branch and opens at a time of the latter half of the exhaust stroke and at the end of the intake stroke, so that the auxiliary valve of one cylinder opens in synchronization with the opening operation of the auxiliary valve of another cylinder. The valve lift or the opening duration of the auxiliary valves of said one cylinder and another cylinder which are arranged adjacent to each other is set so as to be less than that of the auxiliary valves of said one cylinder and another cylinder which are not arranged adjacent to each another.

Abstract: Disclosed is a multi-cylinder engine having auxiliary valves, in addition to intake and exhaust valves. Each of the cylinders is connected to a common accumulation chamber via corresponding branches. Each of the auxiliary valves is arranged in its respective branch and opens over almost the entire period of the compression stroke and at the beginning of the exhaust stroke of the corresponding cylinder.

Abstract: A fuel supply system which preheats fuel to be supplied to a carburetor or a fuel injection device up to a constant temperature regardless of variations in engine operating condition, wherein a part of a fuel supply tube which extends from a fuel pump to the carburetor or the fuel injection device is put into contact with engine cooling water in a heat exchanging manner.