1968 Evinrude Ski-Twin, Ski-Twin Electric 33 HP Outboards Service Manual, Page 51Get this manual
DESCRIPTION RUBBER MOUNTS The exhaust housing assembly, which carries the power head, f10ats the steering bracket and pilot shaft assembly six mounts and two bumpersIn this way, power head and drive shaft vibrations isolated and prevented from being transmitted to the stern bracket and boa transomFigure 6-1RELIEF Norma1ly, exhaust gases conducted down through the exhaust housing and out the underwater outlet in the gearcaseThe siphoning action of the and water provides unrestricted escape for exhaustHowever, in starting, water in the outlet creates back pressureExhaust relief is provided another outlet located in the water discharge passage above the water lineSince water is discharged until after the motor is started, the exhaust gases will initially discharged through the water outlet
IMPELLER
SLOW SPEED
Figure 6-2Impeller Positions WATER PUMP Water for cooling the power head is circulated the water located at the top of the gearcase and driven directly the driveshaftThe consists of synthetic impeller which is keyed to the driveshaft, and the housing which is offset from center with respect to the driveshaftBecause the housing is offset, the impeller blades as they rotate, varying the space between themThe inlet port, located in the stainless steel plate which forms the lower part of the housing, is to the blades when the space between them is increasingThe outlet port, in the imhousing, is to the blades when the space between them is decreasingThus at low speed the impeller works as displacement At higher speeds, water resistance keeps the blades from flexing, and the acts as circulator, enough water being provided the forward motion of the motor through the waterFigure 6-2GEAR The three functions of forward, neutral, and reverse operation provided the gear shift mechanism located in the lower gearcaseFigure 6-3The