362B64105-0 Tohatsu PROPELLER (7), 3 X 9.2 X 6.9

Illustration 1 g00545568
Combined circuit cooling system
(1) Turbocharger
(2) Cylinder block and cylinder head
(3) Right side water pump
(4) Water temperature regulator
(5) Oil temperature regulator
(6) Oil flow
(7) Oil coolers
(8) Mixer housing
(9) Mixer housing
(10) Left side water pump
(11) Air flow
(12) Aftercooler
(13) Expansion tank
(14) Water temperature regulator
(15) Orifice
(16) Heat exchanger or radiator
Illustration 2 g01344630
Combined circuit cooling system
(17) Coolant outlet or heat exchanger
(18) Water temperature regulator housing
(19) Water manifold
(20) Coolant return line from the turbocharger
(21) Turbocharger
(22) Coolant supply line to the turbocharger
(23) Oil coolers
(24) Tube
(25) Aftercooler
(26) Elbow
(27) Right side water pump
(28) Coolant supply to oil cooler
(29) Coolant inlet
(30) Left side water pump
(31) Coolant supply to the aftercooler
(32) Coolant return from the aftercooler In the combined circuit cooling system, coolant is pulled from the expansion tank through inlet (29) by the left side water pump (30). Coolant flow is divided at the water pump. Part of the coolant is sent to the oil coolers (23) while the rest is sent through the aftercooler (25). Coolant from the aftercooler and from the oil coolers goes to the water temperature regulator housing (18).The water temperature regulators (18) allow water that is from the cylinder block to recirculate through the right side water pump (27) or the water temperature regulators allow water from the aftercooler outlet line (25) and from the oil coolers (23) to circulate through the radiator, the heat exchanger or the expansion tank.The right side water pump (27) pulls coolant from the water temperature regulator housing (18) through the tube (24). Coolant from the right side water pump is sent to the cylinder block through the elbow (26).The coolant flows upward through the water jackets and the coolant flows around the cylinder liners from the bottom to the top. Near the top of the cylinder liners, the water jacket is made smaller because the temperature is highest. This shelf (smaller area) causes the coolant to flow faster for better liner cooling. Water is then diverted through passages that are drilled in the cylinder liner. This gives greater cooling at the top ring turn around. Coolant from the top of the liners goes through a collector plate into the cylinder head. This sends the coolant around the parts that have the highest temperature. Coolant then goes to the top of the cylinder head and out through elbows at each cylinder head. The coolant then flows from the elbows to the water manifold (19). From the water manifold, the coolant enters the water temperature regulator housing.Coolant is sent from the water jacket at the rear of the cylinder block through a tube (22) to the turbocharger (21). Coolant from the turbocharger is returned to the manifold through the tube (20).The water temperature regulator housing (18) has an upper flow section and a lower flow section. The water temperature regulator housing uses four temperature regulators. The sensing bulbs of the four temperature regulators are in the coolant in the lower section of the housing. Before the regulators open, cold coolant is sent through the bypass tube (24) to the right side water pump. As the temperature of the coolant increases enough to make the regulators open, coolant flow to the bypass tube is stopped and coolant is then sent through the outlet (17) to the radiator or the heat exchanger.