Patent ID: 7997250

Claim:
An upper structure of an engine having three or more cylinders arranged in a row, comprising: a first spark plug provided in each of said cylinders and disposed approximately on a center line of a corresponding one of said cylinders; a second spark plug provided in each of said cylinders and disposed apart from said first spark plug in a cylinder row direction; and an ignition coil unit connected to each of said first and second spark plugs, said ignition coil unit having a connection pipe portion adapted to be inserted into a plug hole and connected to said first or second spark plug through a distal end thereof, and a head portion provided on the side of a base end of said connection pipe portion and adapted to be exposed above a head cover of said engine, wherein: a first one of a pair of adjacent cylinders among at least three of said cylinders serially arranged in said cylinder row direction is provided with said second spark plug at a position on an opposite side of a second one of said pair of adjacent cylinders; and said second one of said pair of adjacent cylinders is provided with said second spark plug at a position on an opposite side of said first one of said pair of adjacent cylinders.