As normal the standed disclaimer applies. I can accept no responsibilty for the
accuracy of the information contained here or any use you put it too.
This information is NOT to be circulated in any other form
apart from this or in HARD COPY without my consent, I wrote this, so bloody ask
me first, I own it!!
Application of the procedures described
herein is at your own risk. I have submitted this information in good faith,
without charge but neither myself or any other persons will be held responsible
for any injury, damage or loss whosoever caused resulting from your use of
these procedures or Information. This information is not intended to replace
your repair manuals, your common sense, or your responsibility for your choices
and actions.
Having spent a little time on this Wee Beastie lately I
thought it a good idea to commit some of this information to (virtual) paper,
so I can remember what I did. Hopefully this may also come in some use to you,
if you also have problems with this little but expensive 'Black' box.
The Fz is a pumped system, that is
instead of the normal motorcycle fuel delivery system that uses as a delivery
method and very reliable system at that, called gravity it uses a pump and
controller. This is because to get a large gas capacity, held low on the
machine, the bottom of the tank is lower than the carbs, so an electric fuel
pump is used to pump the gas to the carb float bowls.
Tho this is less reliable than the
traditional method is has the benefit of always suppling a good pressure to the
carbs regardless of the head of fuel available. The biggest problem is when a
fault in the system can easily leave you stranded, plus there are so many parts
of the system its prone to one part of link breaking the chain or a bad
connection of a single component causing problems.
The Fuel Gauge sender - In fact contains 2 components: -
The gauge -is a resistor with a float, this gives a varying
resistance to the fuel gauge on the instrument panel, its prone to problems,
and normally wears out the small gauge resistor wire and then goes open circuit
or gives a false reading. There is little that can be done to fix the gauge and
all second hand ones appear broken too.
The Reserve
sensor - Upon the unit is a small sensor that
changes resistance depends upon if its emersed in fuel or not, this sensor is
used to tell the fuel controller if the fuel is below the reserve level.
The sender unit can be removed by taking
out the 10mm bolts from under the tank, take care not to loose the rubber
seals.
The Fuel Pump - Is a self
regulating/self priming electric pump as used on many motorcycles and small
cars. The fuel pressure is very low and replacing the pump with another type is
usually difficult, as the pressure is so small. The pump automatically stops
running when the pressure in the downstream line to the carbs reaches a set
level. IT does this via a central plunger through the middle of the pump and
that breaks a contact on the end of the pump. Its vital that these contacts are
kept clean and the wires are attached (they have a habit of breaking off and the
contacts tend to burn up). The pump is run from the fuel controller via 2 wire
plug. The contacts can be got at be removing the small crosshead screw from the
rubber boot and pulling back the boot.
The Ballast
resistor - This small white ceramic resistor is used to balance the
reserve sensor to increase its effect on the Fuel controller for switching in
reserve. Its important that the resistor contacts are clean. Apart from that it
never goes wrong and is not otherwise serviceable.
The TCI (CDI)
Ignition Unit - The TCI box has a branch wire running from the RH coil
switch line on the big block connector to the fuel controller this tells the
controller that the engine is running and sets the controller mode to normal
RUN when its is active.
The fuel filter - Is a small
inline fuel filter mounted between the outlet tap and the pump, it should be
clamped to the frame and is mounted in a specific direction, its worth cleaning
the filter out every 12 months with compressed air, or simply replace it with a
cheap car item.
The Fuel Tap -
Mounted under the tank is the only way to cut fuel to the pump for tank
removal. The nylon square on the tap is prone to damage. Best solution here is
to leave the tap on open and install a race style self sealing connector on the
fuel line NOTE: the tape does not
control the reserve ,but is basically a maintenance aid when removing the tank.
The fuel controller does one thing really
it control power to the pump. Basically it does this via 3 modes or functions.
Reserve mode- it works the reserve system. When the sensor in the tank
is clear of the fuel (ie fuel has dropped below the level of the sensor, its
change in resistance coupled with the balancing effect of the ballast resistor
tells the controller that it should cut the power to the fuel pump. This
simulates a traditional reserve function. To change to reserve a small bypass
switch on the LH fairing bypass's the sensor and tells the controller to re
power the pump. Its common for the bypass switch to become u/s, so use the
switch and keep the contacts clean with WD40.
Start up mode when the engine is not running (ie the link line from the
ignition is Inactive) means that it supplies a 5 second burst of power to the
pump to pressure the line. After 5 seconds the power is cut. You can reengage
startup mode by flicking the runstop switch to off and back to run, this will
run the pump for 5 seconds.
Run mode- once the engine is started and the TCI line is active the
controller switches to RUN mode and supplies the pump with 12 volts
continually.
The fuel controller DOES
NOT regulate the pressure in the fuel line by turning the pump
on and off this is done by the pump itself.
Reserve
doesn’t work - The reserve system is prone to problems.
If the bike refuses to run on reserve then the first thing to check is the
by-pass switch is clean and the contacts work, this should be easily be
identified via the small connector and your trusty multimeter. If the switch checks out then I am
afraid you have a problem with the fuel controller. Oh dear.
The fuel pump
wont cycle at all -
The pump itself can become inoperable and a common cause of this is
burnt contacts or broken wires in the pump. Remove the small crosshead screw from
the pump and remove the rubber boot to get at the contacts clean them up and
make sure the tiny earth braid is in place. If this checks out then it possible the
controller is faulty. Pull off the big 6 pin plug off the controller and check
that there is 12 volts on the red/white tracer wire. If there is then the
controller is faulty (or the controller is in reserve mode), best run the
controller pin test listed in the manual. If there isnt 12 volts then the there
is a problem with the main power supply.
The fuel
controller wont run the pump when in RUN MODE - Is almost certainly a problem with the
controller, check that you have 12 volts at the red/white tracer wire, if you
do check the controller with the pin test in the manual. If the controller
checks out then check the TCI branch wire is intact.
A sure sign off this is that the pump runs fine every time
you flick the runstop switch but then stops after 5 seconds. The bike starts
fine but runs out of gas after ¼ of a mile. Flicking the runstop starts the
bike off again for another ¼ of a mile, then the same happens again.
The fuel
controller wont run the pump in STARTUP MODE - - Is almost certainly a problem with the
controller, check that you have 12 volts at the red/white tracer wire, if you
do check the controller with the pin test in the manual.
The Tap has
broken – the nylon square on the tap gets all chewed up, best
leave the tap in on position and install a second tap in the shape of a quick
release racing line connector.
The bike
misfires and wont run right – Its vital that the fuel system is
kept clean, clean the components
out with compressed air periodically.
Common problems with the controller and how to bypass it.
The controller is prone to lots of
problems and as it costs about the same as the third world debt some owners are
forced to by-pass the controller.
You will loose your reserve function (not a big hardship if you fuel
gauge works) and the 5 second start mode function will go also.
Connect the red white wire on the 6 pin
controller plug directly to the blue wire on the fuel pump. Best way to do this is to cut the re
wire 1” short of the connect and run a new wire to the blue wire on the same
connector, that way to can still remove the pump via it 2 pin connector. As soon as the ignition is on 12 volts
will be supplied to the pump.
???????????????????????? Can it be done,? can the reserve
function be reinstated??? Im not
bothered about the statup mode, but getting reserve to work again would be nice!!!!
Kev@eddnet.com