3-20 FUEL SYSTEM (DFI)
DFI Servicing Precautions
There are a number of important precautions that should
be followed servicing the DFI system.
This DFI system is designed to be used with a 12 V sealed
battery as its power source. Do not use any other battery
except for a 12 V sealed battery as a power source.
Do not reverse the battery cable connections. This will
damage the ECU.
To prevent damage to the DFI parts, do not disconnect the
battery cables or any other electrical connections when
the ignition SW (switch) is on, or while the engine is run-
Take care not to short the leads that are directly con-
nected to the battery positive (+) terminal to the chassis
When charging, remove the battery from the motorcycle.
This is to prevent ECU damage by excessive voltage.
Whenever the DFI electrical connections are to be discon-
nected, first turn off the ignition SW (switch). Conversely,
make sure that all the DFI electrical connections are firmly
reconnected before starting the engine.
Do not turn the ignition SW ON while any of the DFI elec-
trical connectors are disconnected. The ECU memorizes
Do not spray water on the electrical parts, DFI parts, con-
nectors, leads, and wiring.
If a transceiver is installed on the motorcycle, make sure
that the operation of the DFI system is not influenced by
electric wave radiated from the antenna. Check operation
of the system with the engine at idle. Locate the antenna
as far as possible away from the ECU.
When any fuel hose is disconnected, do not turn on the
ignition SW. Otherwise, the fuel pump will operate and
fuel will spout from the fuel hose.
Do not operate the fuel pump if the pump is completely
dry. This is to prevent pump seizure.
Before removing the fuel system parts, blow the outer sur-
faces of these parts clean with compressed air.
When any fuel hose is disconnected, fuel may spout out
by residual pressure in the fuel line. Cover the hose joint
with a piece of clean cloth to prevent fuel spillage.
When installing the fuel hoses, avoid sharp bending, kink-
ing, flattening or twisting, and route the fuel hoses with a
minimum of bending so that the fuel flow will not be ob-
Route the hoses according to Cable, Wire, and Hose
Routing section in the General Information chapter.
To prevent corrosion and deposits in the fuel system, do
not add to fuel any fuel antifreeze chemicals.
Replace the fuel hose if it has been sharply bent or kinked.