1970 Johnson 115 HP Outboard Motor Service manual, Page 47Get this manual
DESCRIPTION
The power head consists of the cylinders, piStons, connecting rods, crankshaft, and rankcaseThe power head has two banks of horizontally-mounted cylinders in "V" formation 90" apartEach cylinder delivers one power impulse per crankshaft revolution, thus giving one power impulse at every 90 degrees of crankshaft rotation
THEORY OF OPERATION