1974 Johnson 135 HP Outboard Motors Service manual, Page 50Get this manual
DESCRIPTION
The power head cons ists of the cylinders, pistons, connec ting ods, crankshaft, and crankcaseThe power head has two banks of horizontally-mounted cylinders in "V" formation 90 apartEach cylinde delivers one powe impulse per rankshaft revolution, thus giving one powe impulse at every 90 degrees of rankshaft otation
THEORY OF OPERATION