Function Of Major Components - Yanmar 4JH45 Operation Manual

PRODUCT OVERVIEW

FUNCTION OF MAJOR COMPONENTS

Name of Component
Fuel Filter
Fuel pre-filter
(Water separator)
Fuel Priming Pump
Engine Oil Filler Port
Engine Oil Filter
Marine Gear Filler Port
Cooling System
Coolant pump
Seawater Pump
Reservoir
Oil Cooler - Engine
Oil Cooler - Marine Gear
(Optional)
Turbocharger (if equipped)
Air cooler (if equipped)
Intake Silencer (Air Cleaner)
Nameplates
Starter
Alternator
Engine Oil Dipstick
16
The fuel filter removes contaminants and sediments from the diesel fuel. Periodic replacement
of the fuel filter is necessary. See Periodic Maintenance Schedule on page 60 for the
replacement frequency.
The water separator removes contaminants, sediment and water from diesel fuel going to the
fuel filter. This is a required component of the fuel system and is standard equipment with
every engine. The water separator is installed between the fuel tank and the fuel feed pump.
Periodically drain the water from the water separator using the drain cock at the bottom of the
separator and replace the filter element.
This is a manual fuel pump. Pushing the knob on the top of the fuel pre-filter feeds the fuel.
This pump is also used to bleed air from the fuel system.
Filler port for engine oil.
Filters fine metal fragments and carbon from the engine oil. Filtered engine oil is distributed to
the engine's moving parts. The filter is a cartridge type and the element should be replaced
periodically. See Changing the Engine Oil and Replacing the Engine Oil Filter Element on
page 73.
Filler port for marine gear lube oil. Located on top of the marine gear case.
There are two cooling systems: closed cooling with coolant and seawater. The engine is
cooled by the closed cooling circuit. The closed circuit is cooled by seawater using a heat
exchanger. The seawater also cools the engine/marine gear oil and intake air (depending on
model) through the cooler(s) in an open circuit.
The centrifugal water pump circulates coolant inside the engine. The circulating pump is
driven by a V-ribbed belt.
Pumps seawater from outside vessel to the engine. The seawater pump is gear-driven and
has a replaceable rubber impeller. Do not operate it without seawater, as this will damage the
impeller.
The pressure valve in the filler cap releases vapor and hot water overflow to the reservoir.
When the engine stops and the coolant cools, the pressure in coolant tank drops. The filler
cap vacuum valve then opens to send water back from the reservoir. This minimizes coolant
consumption. The closed cooling system coolant level can easily be checked and refilled in
this tank.
A heat exchanger that cools high temperature engine oil using coolant.
This heat exchanger cools the marine gear (KMH4A) oil using seawater.
The turbocharger pressurizes the air coming into the engine. It is driven by a turbine that is
energized by exhaust gases.
This heat exchanger cools the pressurized charging air from the turbocharger with seawater
to increase the charging air quantity.
The intake silencer guards against dirt in the air and reduces the noise of air intake.
Nameplates are provided on the engine and the marine gear and have the model, serial
number and other data.
Starter motor for the engine. Powered by the battery.
Driven by belt and generates electricity and charges the battery.
Gauge stick for checking the engine oil level.
Function
JH Series Operation Manual