Components; Water Pump And Intakes; Water Supply Tube; Adapter Housing - BRP E250DHLSCS Service Manual

COMPONENTS

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 liner must seal
•
against a separate water pump plate.
The bottom plate MUST seal to gearcase.
•
The pump operates as a positive displacement
•
pump at LOW speeds (below 1500 RPM) and
as a centrifugal pump at HIGHER speeds.
Refer to WATER PUMP SERVICE on p. 274 for
water pump servicing.
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.
Adapter/Inner Exhaust Housing
Adapts the cylinder/crankcase assembly (pow-
•
erhead) to the exhaust housing and the water
tube.
Provides water passages which route incoming
•
and outgoing cooling water.
Provides exhaust passages which connect to
•
the gearcase.
3

1. Adapter housing

5

Pressure Relief Valve

A pressure relief valve is used to control water
4
flow and operating temperature at higher speeds
(above approximately 1800 RPM). The pressure
relief valve opens as water pressure increases.
Spring tension sets the opening pressure.
000697
Overheating: A restricted or faulty valve typically
DSC02328
results in HIGH SPEED overheating.
COOLING SYSTEM
COMPONENTS
006991
203
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