Patent ID: 6186846
Filing Date: 2001-02-13
Classification: B63H,F01N,F02B,Y02T

Abstract:
An exhaust passage structure for an outboard motor equipped with an engine having a cylinder block comprising:a plurality of cylinders arranged in a line, with an exhaust port for each cylinder being formed in a cylinder head that is joined with the cylinder block;a plurality of exhaust passages formed in an exhaust manifold for connecting each exhaust port and an exhaust discharge path formed on a side of the outboard motor, the plurality of exhaust passages including first and second exhaust passages for respective first and second cylinders in which combustion takes place in odd-numbered cycles, and third and fourth exhaust passages for respective third and fourth cylinders in which combustion takes place in even-number cycles; andwherein the plurality of exhaust passages are joined before the first and second exhaust passages are separately joined so that the first and second exhaust passages are disposed in parallel to each other relative to a longitudinal direction of the outboard motor.