GENERAL SERVICE INFORMATION
Diesel Fuel
12/05
BY Service Manual
3-13
© 2009 Yanmar Marine International
Precautions and concerns regarding the use of
bio-fuels:
• Biodiesel fuels have a higher content of
methyl-esters, which may deteriorate certain
metal, rubber and plastic components of the fuel
system. The customer and / or boat builder are
responsible to verify the usage of biodiesel
compatible components on the vessel fuel supply
and return systems.
• Free water in biodiesel may result in plugging of
fuel filters and increased bacterial growth.
• High viscosity at low temperatures may result in
fuel delivery problems, injection pump seizures
and poor injection nozzle spray atomization.
• Biodiesel may have adverse effects on some
elastomers (seal materials) and may result in fuel
leakage and dilution of the engine lubricating oil.
• Even biodiesel fuels that comply with a suitable
standard as delivered, will require additional care
and attention to maintain the quality of the fuel in
the equipment or other fuel tanks. It is important
to maintain a supply of clean, fresh fuel. Regular
flushing of the fuel system, and / or fuel storage
containers, may be necessary.
• The use of biodiesel fuels that do not comply with
the standards as agreed to by the diesel engine
manufacturers and the diesel fuel injection
equipment manufacturers, or biodiesel fuels that
have degraded as per the precautions and
concerns above, may affect the warranty
coverage of the engine.
Diesel Fuel Lines
Shown is a typical installation of a boat fuel system.
Fuel supply (Figure 3-10, (2)) and return
(Figure 3-10, (4)) lines connect to fittings at the
engine.
Figure 3-10
Figure 3-10
1 – Optional Boat Builder Installed Fuel
Filter / Water Separator*
2 – To Fuel Feed Pump
3 – Less than 500 mm (19.68 in.)
4 – Fuel Return Line
5 – Fuel Tank
6 – Fuel Tank Drain Cock
7 – 20 to 30 mm (0.75 to 1.125 in.)
8 – Fuel Shutoff Valve
*Note:Yanmar supplies a water separating pre-filter
for mounting by the installer. The engine is
also equipped with an on-engine fine filter.
NOTICE: The fuel supply line between the fuel tank
and engine must be a minimum diameter of 8 mm
(0.315 in.).
Install a drain cock (Figure 3-10, (6)) at the bottom
of the fuel tank to remove water and contaminants.
Boat fuel supply system restriction must not exceed
1000 mmAq (39.37 in.Aq).
Boat fuel return system restriction must not exceed
200 mmAq (7.87 in.Aq).
000
3
6
38
(2)
(1)
(4)
(6)
(
8
)
(5)
(7)
(
3
)
