1975 Evinrude 40 HP Outboards Service Manual, PN 5093, Page 45Get this manual
DESCRIPTION The power head consists of the cylinders, pistons, rods, crankshaft, and crankcaseThe power head has two horizontally mounted cylinders Alternate firing order is used so that each cylinder delivers one power impulse per crankshaft revolutionSee Figures 5-1 and 5-2
EXHA UST PORT EXHA UST GASES