Water Flow And Hose Routing Diagrams; Water Flow - BRP Evinrude E-TEC G2 Service Manual

Cooling System

Water Flow and Hose Routing Diagrams

Water Flow and Hose Routing Diagrams

Water Flow

Refer to the water flow diagram on the next page, or in the Diagrams section of this manual.
Cooling water (1) flows from the gearcase water inlet screens to the water pump (2). From the water
pump, cooling water flows through a water tube (3) inside the exhaust housing (4) to the exhaust adapter
(5).
From the exhaust adapter, water flows into the cylinder block (6). After the cylinder block water passages
have filled, some water exits through a water filter (7) at the top of the block and flows to a tee fitting.
From the tee fitting, water to cool the DPS module (8) flows through a hose and fitting to the exhaust
adapter. This water cools the exhaust and then exits through the propeller hub (24). Water to cool the
EMM (9) and vapor separator (10) exits the overboard indicator (11).
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Some water from the exhaust adapter also cools the exhaust manifolds (13 & 14 ). Vents (15) at the top
of the exhaust manifolds allow any air to purge from the cooling system. Air and water exiting the vents
flow to the overboard indicator (11).
Water dams (12) in the cylinder block (6) direct water to cool the starboard & port cylinder sleeves (16 &
† †
17 ) then flows into the bottom of the cylinder heads (18 & 19 ). After the cylinder head water passages
fill, water flows out through a fitting (21) on the port side of each cylinder head. A hose assembly carries
the water to the port side of the exhaust adapter (5).
†
When the engine reaches operating temperature, the thermostats (20 & 23 ) open. Water from the ther-
mostats flows through a hose assembly to the rear of the exhaust adapter (5).
When the engine is accelerated and water pressure reaches approximately 28 psi (193 kPa), the water
pressure relief valve (22) opens and water flows out of the valve and into the exhaust housing (4).
All water flowing to the exhaust housing and exhaust adapter (4 & 5) exits through the water outlets at
the top of the gearcase.
†
NOTE: Port exhaust manifold, sleeves and cylinder head are NOT shown. Water flow to port exhaust
manifold, sleeves and cylinder head follows a path similar to the starboard side.
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