Snowmobile Arctic Cat (2000 year). Manual - part 68

4. If an adjustment is necessary, loosen the switch

bracket screws, move the switch up, tighten the
screws, and then reset using step 3.

NOTE: After completion of any adjustments,

throttle lever “side pressure” should not cause an
ignition miss at idle. Carburetor switches set too
low or an excessively tight throttle cable makes the
shutdown system very sensitive to throttle lever
“side pressure” near idle. To test carburetor safety
switch synchronization, follow steps 5-9.

5. Reconnect the carburetor safety switch connectors.

Place the rear of the snowmobile on a shielded
safety stand; then start the engine and allow it to
warm up for 3-4 minutes.

6. Hold both the top and bottom of the throttle lever

pin so that depression of the throttle lever does not
move the lever pin in its control slot.

Fig. 5-5

0728-916

7. Slowly depress the throttle lever to increase engine

RPM.

NOTE: It is very important that engine RPM be

allowed to increase slowly, since most engines have
a “rich area” at approximately 2500 RPM.

8. Observe the tachometer and the drive clutch to

determine the moment the carburetor safety
switches shut down the ignition. Since retaining the
throttle lever pin prevents the switch in the throttle
control housing from closing, the carburetor safety
switches should shut down the ignition at or
slightly after clutch engagement.

9. Repeat steps 6-8 several times. If ignition shutdown

a lway s o cc u r s a t o r s l i g h t l y af t e r cl u t ch
engagement, the carburetor safety switches are
synchronized.

10. Again, inspect the gap between the throttle lever

and the control housing at idle. Adjust the throttle
cable swivel adapter at the top of each carburetor
for 0.75-1.5 mm (0.030-0.060 in.) cable free-play
gap between the throttle lever “nibs” and the control
housing. While observing if there is any cable
free-play gap, apply slight pressure to the throttle
lever to take up any cable slack that may be present.
However, do not apply enough pressure to actually
raise the carburetor slides during this adjustment.
After cable free-play is properly adjusted, tighten
the jam nut on each carburetor securely.

NOTE: After completion of any adjustments,

throttle lever “side pressure” should not cause an
ignition miss at idle. Carburetor safety switches set
too low or an excessively tight throttle cable makes
the shutdown system very sensitive to throttle lever
“side pressure” near idle.

Troubleshooting

Ignition System

(Twin & Triple L/C Models)

When troubleshooting the standard “normally open”
ignition system, use the following procedure.

1. Remove the spark plugs and visually check their

condition. Replace any fouled plug. Attach the
spark plugs to the high tension leads and ground
them on the cylinder heads.

Before checking for spark, place all the engine
switches in the deactivated position. In the event
the engine could be flooded, pull the starter rope
(slowly at first) several times to clear the engine
of excess fuel.

Never crank the engine over without grounding
the spark plugs. Damage to coils and/or CDI unit
may result.

NOTE: Make sure the ignition switch and the

emergency stop switch are in the ON position.

2. Crank the engine over and check for spark. If no

spark is present, check to make sure the carburetor
throttle cables are properly tensioned. Compress
the throttle control and while holding the throttle
control in this position, crank the engine over and
check for spark. If spark is now present, adjust the
carburetor throttle cable tension.

! CAUTION

5-18

3. If no spark is present, disconnect the main wiring

harness from the engine. Crank the engine over. If
spark is present, the problem is either one or more
of the following:

a. Defective emergency stop switch

b. Defective safety switch in throttle-control

handle

c. Corroded or loose wire connection at the

throttle-control housing or main wiring harness

d. Defective ignition switch

NOTE: To check these possible causes, proceed

to Testing Ignition System. If no spark is present,
proceed to Arctic Cat Ignition Analyzer in this
section.

Testing Ignition

System

(Twin & Triple L/C Models)

NOTE: There must be 0.75-1.5 mm (0.030-0.060

in.) throttle cable free-play (on the VM-style
carburetor models) or no free-play (on the TM-style
carburetor models) between the throttle lever and
the control housing.

MAIN WIRING AND SAFETY SWITCHES

1. Check the wiring connections coming from the

ignition key, emergency stop, and carburetor
switches (on VM-style). The throttle control switch
connector is located on the front side of the steering
post. If any of the connections appear dirty or
corroded, clean them with fine sandpaper and
compressed air; then connect all wires and squeeze
the connections with a pliers for additional
tightness.

2. Disconnect the main wiring harness connector

c o m in g from t he engine stator ass emb ly.
Disconnecting this connector will bypass the main
wiring harness and all switches which will not
allow the engine to be shut off without first
installing an additional auxiliary ground wire.

3. Insert an auxiliary ground wire into the black wire

of the main harness connector on the engine side.
To stop the engine once it has been started, touch
the auxiliary ground wire to the engine.

4. Support the rear of the snowmobile up on a shielded

safety stand; then set the brake lever lock. Inspect
the complete throttle mechanism to assure that it’s
working properly.

5. Attempt to start the engine. To stop the engine (if

the engine starts), touch the auxiliary ground wire
installed into the connector to a ground on the
engine. If the engine fails to start, the problem is
with the coils mounted on the engine, high tension
coil assembly, or the CDI unit. If the engine starts,
the problem is with the switches, main wiring
harness, or throttle cable free-play.

MAIN HARNESS

1. Disconnect the main wiring harness connector

coming from the engine stator assembly. Connect
one ohmmeter lead to the violet wire and the other
lead to the brown wire on the chassis side of the
main wiring harness four-wire connector. With all
switches in the RUN position, the meter must read
no resistance (open).

2. If the meter reads resistance (closed), test the

Ignition Key Switch, Throttle Control Switch, and
Carburetor Safety Switches independently of each
other.

IGNITION KEY SWITCH

1. Disconnect the ignition key switch connectors; then

connect the ohmmeter leads to each of the ignition
key switch terminals.

2. With the switch in the OFF position, the meter must

read less than 1 ohm resistance.

3. With the switch in the ON position, the meter must

read OL (infinite resistance).

THROTTLE CONTROL SWITCH

1. Verify that the throttle cable has 0.75-1.5 mm

(0.030-0.060 in.) free-play (VM-style carburetor
models) or no free-play (TM-style carburetor
models) between the throttle lever and control
housing.

2. Disconnect the throttle control switch connector;

then connect one ohmmeter lead to the brown wire
and the other lead to the black/white wire of the
emergency stop switch.

3. With the throttle lever in the idle position and the

emergency stop knob in the up (RUN) position, the
meter must read no resistance (open). If the meter
reads resistance (closed), replace the switch.

4. With the throttle lever in the idle position and the

emergency stop knob in the down (STOP) position,
the meter must read resistance (closed). If the meter
reads no resistance (open), replace the switch. With
the emergency stop knob still in the down (STOP)
position, move the throttle lever to the wide open
position. The meter must read no resistance (open).
If the meter reads resistance (closed), replace the
switch.

5-19

5. Connect one ohmmeter lead to the brown wire and

the other lead to the violet wire. With the
emergency stop knob in the down (STOP) position,
the meter must read resistance (closed). If the meter
reads no resistance (open), replace the switch. With
the emergency stop knob in the up (RUN) position,
the meter must read no resistance (open). If the
meter reads resistance (closed), replace the switch.

CARBURETOR SAFETY SWITCHES
(VM-Style)

1. Disconnect both carburetor safety switches at the

carburetors from the main wiring harness.

2. Connect the ohmmeter leads to one of the

carburetor safety switches. With the throttle lever in
the idle position, the ohmmeter must read no
resistance (open). If the meter reads resistance
(closed), adjust the switch (see Synchronizing
Carburetor Safety Switches in this sub-section).
Test the remaining switch.

SYNCHRONIZING CARBURETOR
SAFETY SWITCHES (VM-Style)

Before synchronizing the carburetor safety switches,
check to make certain the carburetor idle speed screws
are adjusted equally and the throttle valves are
synchronized. The carburetor safety switches affect
ignition spark at idle only. If ignition spark problems are
observed at partial or full-throttle positions, the problem
is not with the carburetor safety switches.

NOTE: The throttle control is equipped with a

3-wire throttle control switch connector. There must
be 0.75-1.5 mm (0.030-0.060 in.) free-play between
the lever and the control housing.

1. Inspect the cable free-play gap between the throttle

lever and the control housing at idle. Adjust the
throttle cable swivel adapter at the top of each
carburetor for 0.75-1.5 mm (0.030-0.060 in.) cable
free-play gap between the throttle lever “nibs” and the
control housing. While observing if there is any cable
free-play gap, apply slight pressure to the throttle
lever to take up any cable slack that may be present.
However, do not apply enough pressure to actually
raise the carburetor slides during this adjustment.
After cable free-play is properly adjusted, tighten the
jam nut on each carburetor securely.

Fig. 5-6

733-081c

2. To determine which switch needs adjusting,

disconnect both carburetor safety switches from the
main wiring harness connector.

3. Connect a digital ohmmeter to one carburetor

safety switch connector; then compress the throttle
lever while observing the meter reading and
measure the gap between the throttle lever and
control housing at the moment the meter reading
changes from open to closed. Repeat this step for
the other carburetor safety switch.

NOTE: The correct throttle lever/housing gap

should be in a range of 9.5 - 12.7 mm (0.375-0.500
in.) the moment the meter reading changes from
open to closed. A switch that changes from open to
closed before the other one is the switch that must
be raised to attain safety switch synchronization.

Fig. 5-7

733-082A

4. If an adjustment is necessary, loosen the switch

bracket screws, move the switch up, tighten the
screws, and then reset using step 3.

NOTE: After completion of any adjustments,

5-20

5. Reconnect the carburetor safety switch connectors.

Place the rear of the snowmobile on a shielded
safety stand; then start the engine and allow it to
warm up for 3-4 minutes.

6. Hold both the top and bottom of the throttle lever

pin so that depression of the throttle lever does not
move the lever pin in its control slot.

Fig. 5-8

0728-916

7. Slowly depress the throttle lever to increase engine

RPM.

NOTE: It is very important that engine RPM be

allowed to increase slowly, since most engines have
a “rich area” at approximately 2500 RPM.

8. Observe the tachometer and the drive clutch to

9. Repeat steps 6-8 several times. If ignition shutdown

a lway s o cc u r s a t o r s l i g h t l y af t e r cl u t ch
engagement, the carburetor safety switches are
synchronized.

10. Again, inspect the gap between the throttle lever

NOTE: After completion of any adjustments,

Digital 3-D Ignition

(700/800/1000 cc)

The advantage of a 3-D ignition system is it actually has
up to twelve slightly different timing curves which are
controlled by both throttle position and engine RPM.
This sytem allows the technician to match a more safe
timing curve to each engine operating condition.

A condition in which the 3-D ignition will have a
distinct advantage is when the operator completes
high-speed operation and backs the throttle position off
slightly to cruise. Since the engine now may still be at
fairly high RPM, it is running at less throttle opening.
This condition can create a higher engine operating
temperature because of the slightly leaner jet needle
position. With the 3-D ignition as soon as the throttle
position is backed off, the ignition timing will be
reduced and engine temperature also will be reduced.

When checking the ignition timing, a couple points
must be remembered. First, since the ignition timing is
affected by the throttle position, the throttle position
sensor (TPS) must be in good operating condition and
adjusted correctly. Second, the ignition timing must be
checked according to the following chart. Never remove
the drive belt to make the timing check. Always place
the rear of the snowmobile on a shielded safety stand
and allow the track to rotate freely.

Engine

RPM

Ignition

Timing ± 2°

Fail-Safe

Timing ± 2°

700 cc

4000

27°

15°

800 cc

1800

12°

N/A

1000 cc

4000

16°

14°

When checking ignition timing, it is important that the
timing light be connected to the number 1 spark plug
wire, which is the MAG-side cylinder. If the number 2
cylinder spark plug wire is used, the timing light may
show a 2° error in ignition timing when ignition timing
is actually correct.

For example, the correct ignition timing on the 700 cc
is 27° + 2° BTDC at 4000 RPM.

If ignition timing is at 15° BTDC at 4000 RPM, the
throttle position sensor (TPS) has failed and must be
replaced. This is known as “Fail-Safe Ignition Timing”
and is built into the system to protect the engine should
the TPS fail.

If the ignition timing isn’t 27° + 2° at 4000 RPM, the
TPS should be checked for proper adjustment using the
TPS Adjustment Tool (p/n 0644-299). To adjust the
TPS, use the following procedure.

5-21

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