Components; General Description; Water Pump And Intakes; Water Supply Tube - BRP Evinrude E-Tec Series Service Manual

COOLING SYSTEM

COMPONENTS

COMPONENTS

General Description

All models use a two-stage cooling system
design. The cooling system is dependent on water
pump pressure and controlled by thermostat and
pressure valve operation.
Restricted or inadequate water
IMPORTANT:
flow through the outboard reduces cooling system
performance and may lead to severe powerhead
damage.

Water Pump and Intakes

External water intakes mounted in the gearcase
housing collect water and must supply the inlet
side of the water pump with an unrestricted and
unaerated water supply. Water is drawn into the
water pump through a hole in the lower plate of
the water pump assembly. All cooling water to the
powerhead is provided by the water pump.
A nylon wedge (impeller key) is used to engage
•
the impeller bushing and driveshaft.
The nylon impeller housing with stainless steel
•
liner must seal against a separate stainless
steel water pump plate.
The pump operates as a positive displacement
•
pump at LOW speeds (below 1500 RPM) and
as a centrifugal pump at HIGHER speeds.
The bottom plate MUST seal to gearcase hous-
•
ing.
Refer to WATER PUMP on p. 311 for water pump
servicing.
230
2
1
(Impeller key removed for clarity)
1. Water inlet
2. Water outlet
3. Seal
4. Plate
5. O-ring

Water Supply Tube

The water pump outlet connects with the water
supply tube located in the outboard's midsection.
Grommets seal the water tube to the water pump
housing and the inner exhaust housing.
Water supplied to the water tube provides all cool-
ing water to the adapter housing and cylinder
block.
3
5
4
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