Snowmobile Arctic Cat (2004 year). Manual - part 41
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3
FC024
5. Place the valve cover into position on the engine.
Secure with two cap screws. Tighten to 0.9-1.3 kg-
m (6.5-9.5 ft-lb).
FC023
6. Perform steps 6-10 in appropriate Cable
Adjustment in this sub-section.
TROUBLESHOOTING
(Carbureted Models)
The APV system has a self-cleaning and self-testing
mode built in. Every time that the engine is started, the
servo will cycle once, and this will wipe-off the carbon
that has accumulated on the exhaust valves. The CDI
unit also monitors the voltages at the servo during this
cycle to assure they are within operational tolerances.
If all voltages are within tolerance, the system is ready
for operation. If the voltages are not within tolerance,
the servo will cycle two more times. If the voltages
remain out of tolerance, the system will not operate.
TROUBLESHOOTING (EFI Models)
The APV system used on EFI models is very similar to
that found on carbureted models. The self-cleaning
and self-testing modes are much alike. The main dif-
ference between the two is the higher total electrical
power required by the EFI and APV systems com-
bined. Because of these more demanding power
requirements, the EFI APV system gets power from
the stator lighting coil. The ECU constantly monitors
the power output of the lighting coil, and if the lighting
coil output gets too high or too low, the ECU will acti-
vate the “limp-home” mode. The “limp-home” mode
is an ECU operated engine RPM limiter. When acti-
vated, the “limp-home” mode will be seen as an imme-
diate loss of engine horsepower.
For example, if the headlight and taillight are disabled,
the ECU will sense a high voltage condition and acti-
vate the “limp-home” mode. Adding more than 4 amps
of accessories will create a low voltage condition and
activate the “limp-home” mode.
NOTE: When running an APV equipped EFI
engine on a dynamometer, first connect a Voltage
Regulator (p/n 0603-142, 2-wire) or (p/n 0630-643,
3-wire) between the lighting coil and the ECU.
There must also be a minimum 2.5 amp load
installed in-line between the voltage regulator and
the ECU (a 2.5 amp load is equivalent to one high
beam headlight bulb).
Troubleshooting EFI engines with the APV system
should be done with the Arctic Cat EFI Analyzer (p/n
0644-342). To update your existing EFI Analyzer,
order Kit (p/n 0644-341).
Problem: Engine loses power; no top end
Condition
Remedy
1. Exhaust valves sticking in
down position
2. Cables adjusted too long
1. Remove carbon deposits,
burrs, etc.
2. Inspect—adjust
Problem: Poor acceleration; hesitation
Condition
Remedy
1. Exhaust valve sticking in
up position
2. Cables adjusted too short
1. Remove carbon deposits,
burrs, etc.—inspect/
replace return spring
2. Inspect—adjust
Problem: Engine loses power; no top end
Condition
Remedy
1. Exhaust valves sticking in
down position
2. Cables adjusted too long
3. Lighting coil output
voltage out of tolerance
1. Remove carbon deposits,
burrs, etc.
2. Inspect—adjust
3. Inspect—replace stator
Problem: Poor acceleration; hesitation
Condition
Remedy
1. Exhaust valve sticking in
up position
2. Cables adjusted too short
3. Lighting coil output
voltage out of tolerance
1. Remove carbon deposits,
burrs, etc.—inspect/
replace return spring
2. Inspect—adjust
3. Inspect—replace stator