Regal 42 Fly-Grande Coupe, Owner'S Manual

Page: 56 / 386

3
Systems
DIESEL FUEL BASICS
Diesel fuel properties have changed in recent years
due to the way the product is processed today at the
refi neries.A couple of decades ago diesel fuel, gasoline,
home heating oil among other distillation products
were processed by heating the crude oil. At diff erent
boiling temperatures, various parts of the crude oil were
evaporated then condensed sending the fi nal products
to storage tanks for distribution. Th
e distillation process
generally produced stable diesel fuel with a storage life
of several months. Around 50% of the oil left over from
the distillation process was designated as heavy fuel oil
being used for ship’s, power plants, and industrial prod-
ucts such as nylon, plastics, and asphalt.
Refi ning crude oil today has changed dramatically due
to increased demand for the product. A process called
“chemical cracking” has allowed the refi ner to extract
more of the lighter distillates from the crude oil leav-
ing about 16% of the residual as heavy fuel oils. Lower-
ing the diesel fuel sulphur levels due to environmental
concerns has led to further fuel instability. Due to these
newer methods of refi ning diesel fuel is far less stable
than the older distillation process.
Th
ere are diff erent theorems on defi ning fuel system
“algae” and how it develops in the vessel’s fuel tank. Al-
gae is slang for the fungus that grows in fuel tanks.
One school of thought isolates two of the key fuel com-
ponents. Asphaltites and paraffi
ns in this premise begin
to oxidize and re-polymerize forming clusters resulting
in fuel tank “algae”. As these clusters “grow” in size they
cling themselves to tank walls and baffl
es.
Others state that “algae” is formed when water con-
denses in the boat’s fuel tank. Water can enter the ves-
sel’s fuel tank through the fuel pumping process at the
fuel dock since their tank may already be contaminated
with algae-micro organisms. Once inside the tank these
algae-microscopic organisms from the plant kingdom
are able to combine with water and diesel to form tank
sludge.
Keeping tanks free from water, dirt and micro organ-
isms is almost impossible, but luckily you can eliminate
them before they reach the engine and fuel injectors
through the use of primary and secondary fuel fi lters.
Algae ends up in the fuel system once the boat is run-
ning which breaks up the tank “algae” and/or sludge
into mini clusters.
Using diesel fuel in this condition may cause the follow-
ing:
• Fuel tank sludge-remove manually or by chemicals
• Dirty engine oil
• Shortened engine component life
• Smoke emitting from the engine exhaust system
• Carbon deposits in the engine
• Incomplete combustion
• Loss of power and performance
• Clogged primary and secondary fuel fi lters
• Malfunctioning fuel injectors
When this condition is present in the marine diesel fuel
system the fuel does not combust rapidly as it should
resulting in a loss of engine effi
ciency.
Basically, with either school of thought this “algae” or
fuel tank sludge is the result of aging diesel fuel. It can
occur in as little as 60-90 days depending on the condi-
tion of the tanks and environment where the diesel fuel
is stored.