RNLI Atlantic 85, Manual

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Activity 9 - Propulsion and Auxiliary Systems
B Class Atlantic 85 Manual – First Issue, June 2017
Activity 9 - Propulsion and Auxiliary Systems
Cooling system
Both the F115 (OE 26) and F115A (OE 33) are directly
cooled by raw seawater. The water is drawn through a
strainer in the outboard’s gear leg and pumped up to the
power head by a rubber-bladed impeller pump, driven
by the output shaft. The water cools the oil pan before
entering the exhaust cover and filling the cylinder head.
There is a feed off to the fuel cooler that cools unused fuel
from the fuel rail. RNLI outboards are fitted with the usual
telltale pipe to indicate the water pump’s output.
Once the engine reaches operating temperature, the
thermostat opens allowing water to fill the upper case,
building up a water wall before venting out via the upper
tell tale and exit holes below the water.
NOTE
Although the intake is fitted with a strainer, this will
only stop large objects entering the cooling system.
Sand, gravel and mud can still get in and block
some or all of the internal waterways. It is therefore
important to flush out the cooling system with fresh
water. Always use the engine flush adaptor or ‘water
(ear) muffs’ after every use.
Pressure control
valve (PCV)
Tell tale
Thermostat
Fuel cooler
Exhaust guide
Oil pan
Water pump
Cooling water inlet
Cylinder head
Engine cooling
Fuel cooling