196
COOLING SYSTEM
COMPONENTS
Adapter Housing
•
Adapts the cylinder/crankcase assembly (pow-
erhead) to the megaphone and exhaust hous-
ings and the water tube.
•
Provides water passages which route incoming
and outgoing cooling water.
•
Provides exhaust passages which connect to
the inner exhaust of the outboard’s midsection.
Pressure Relief Valve
A pressure relief valve is used to control water
flow and operating temperature at higher speeds
(above approximately 2000 RPM). Pressure relief
valve activates or “blows-off the seat” as water
pressure increases. Spring tension is used to set
the “blow off” pressure.
Overheating:
A restricted or faulty valve typically
results in HIGH SPEED overheating.
Overcooling:
Debris may prevent the valve from
closing completely.
The pressure relief valve diaphragm allows the
valve plunger to lift off the seat completely. This
improves the self cleaning properties of the pres-
sure relief valve.
1.
Megaphone
2.
Exhaust housing
3.
Water tube
4.
Adapter housing
5.
Inner exhaust housing
002436
3
5
2
4
1
Pressure relief valve components
002437
Summary of Contents for E-tec 75 HP
Page 1: ......
Page 233: ...233 POWERHEAD POWERHEAD VIEWS 10 POWERHEAD VIEWS Port Short Block Starboard Short Block ...
Page 234: ...234 POWERHEAD POWERHEAD VIEWS Port Dressed Powerhead Starboard Dressed Powerhead ...
Page 235: ...235 POWERHEAD POWERHEAD VIEWS 10 Front ...
Page 236: ...236 POWERHEAD POWERHEAD VIEWS Rear ...
Page 237: ...237 POWERHEAD POWERHEAD VIEWS 10 Top ...
Page 298: ...S 2 ...
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