186
COOLING SYSTEM
COMPONENTS
COMPONENTS
Water Pump and Intakes
External water int akes mo unted in t he ge arcase
housing collect water a nd must su pply the inlet
side of the wa ter pu mp with a n un restricted an d
unaerated water su pply. Water is drawn into the
water pump throu gh a h ole in th e 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 lin er must seal
against a separate water pump plate.
• The bottom plate MUST seal to gearcase.
• The pump opera tes as a p ositive displacement
pump at LOW speed s (below 1500 RPM) and
as a centrifugal pump at HIGHER speeds.
Refer to WATER PUMP SER VICE o n p. 292 for
water pump servicing.
Water Supply Tube
The wa ter pump outlet co nnects with the wa ter
supply tube located in th e outboard’s midsection.
Grommets seal the water tube to the water pump
housing and the inner exhaust housing.
On 3.3 L mod els, the water tube faste ns to the
inner exhaust hou sing with a water plate a nd
screws.
Water supplied to the water tube provides all cool-
ing water to the adap ter housing and cylind er
block.
Adapter Housing
• Adapts the cylind er/crankcase assembly (pow-
erhead) to the exha ust hou sing and the wa ter
tube.
• Provides water passages which rout e incoming
and outgoing cooling water.
• Provides exhaust p assages which connect to
the gearcase.
(Impeller key removed for clarity)
1. Water inlet
2. Water outlet
3. Seal
4. Plate
5. O-ring
000697
DSC02328
1. Adapter housing – 3.3 L models 000695
1. Adapter housing – 3.4 L models 006991
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