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Snowmobile Arctic Cat (2002 year). Manual - part 73

5-11

Electrical

Specifications

(800 cc - Carbureted)

NOTE: The ignition system is a Normally Open Ignition (NOI).

* Engine RPM is approximate. Tests were made by pulling the recoil starter rope briskly, not with the engine

running.

NOTE: Lighting coil output is unregulated voltage.

Description

Resistance Test

Test Value

+ Test Connections -

Ignition Coil

Primary
Secondary

0.24-0.36 ohm

6800-10,200 ohms

orange

high tension wire

black

high tension wire

DC Power Coil

0.52-0.78 ohms

red/yellow

yellow/red

Lighting Coil

0.08-0.12 ohm

yellow

Ignition Timing Sensor

148-222 ohms

green/white

brown

Spark-Plug Cap

4000-6000 ohms

cap end

Description

Test Value

+ Test Connections -

Voltage Regulator

11-13 AC volts

@ 2500-2700 RPM

red

brown

Low Oil-Light Sending

Unit

Less than 1 ohm

(float end down)

terminal

High Temperature

Sensor

Open (water temperature

lower than 190°F)

terminal

ground

Up to 20 ohms

(water temperature

higher than 230°F)

terminal

ground

High Temperature

Warning Light

Less than 10 ohms

terminal

Ignition Switch

Less than 1 ohm

(key in OFF position)

terminal

Description

Peak Voltage Test

RPM*

2000*

Primary Coil

170-187V

Secondary Coil

105-116V

DC Power Coil

14.0-15.5V

Lighting Coil

7.0-7.7V

Description

Standard

Ignition Timing

14° BTDC @ 2000 RPM

1.417 mm (0.056 in.)

Lighting Coil Output

12V/210W

Ignition Type

CDI/NOI

(Normally Open Ignition)

Spark Plug

NGKBR9EYA

Spark-Plug Gap

0.7-0.8 mm

(0.028-0.031 in.)

5-12

Electrical

Specifications

(1000 cc)

NOTE: The ignition system is a Normally Open Ignition (NOI).

* Engine RPM is approximate. Tests were made by pulling the recoil starter rope briskly, not with the engine

running.

NOTE: Lighting coil output is unregulated voltage.

Description

Resistance Test

Test Value

+ Test Connections -

Ignition Coil

Primary
Secondary
(Dual Lead)
(Single Lead)

0.29-0.39 ohm

6320-9480 ohms
6320-9480 ohms

positive spade terminal

high tension wire
high tension wire

negative spade terminal

high tension wire

positive spade terminal

Charge Coil (1)

12-18 ohms

black/red

green/red

Charge Coil (2)

12-18 ohms

brown/white

green/red

Lighting Coil

0.12-0.18 ohm

yellow

Ignition Timing Sensor

152-228 ohms

green/white

brown

Spark-Plug Cap

4000-6000 ohms

cap end

Description

Test Value

+ Test Connections -

Voltage Regulator

11-13 AC volts

@ 2500-2700 RPM

yellow

brown

Low Oil-Light Sending

Unit

Less than 1 ohm

(float end down)

terminal

High Temperature

Sensor

Open (water temperature

lower than 190°F)

terminal

ground

Up to 20 ohms

(water temperature

higher than 230°F)

terminal

ground

High Temperature

Warning Light

Less than 10 ohms

terminal

Ignition Switch

Less than 1 ohm

(key in OFF position)

terminal

Description

Peak Voltage Test

RPM*

2000*

Primary Coil

185-204V

Secondary Coil

100-110V

Charge Coil (1)

69-76V

Charge Coil (2)

79-87V

Lighting Coil

7.0-7.7V

Description

Standard

Ignition Timing

16° BTDC @ 3250 RPM

1.556 mm (0.061 in.)

Lighting Coil Output

12V/185W

Ignition Type

CDI/NOI

(Normally Open Ignition)

Spark Plug

NGKBR9EYA

Spark-Plug Gap

0.7-0.8 mm

(0.028-0.031 in.)

5-13

Transistorized Ignition

System

(120 cc Model)

The transistorized ignition system has no contact

points. Therefore, this ignition system does not require

periodic reconditioning of contact point surfaces or

point gap adjustment. As a result, a strong spark is pro-

duced even at low speeds so maximum reliability can

be ensured.

OPERATION

GEN-0008

When the recoil starter handle is pulled, the flywheel is

turned. An electromotive force generated in the pri-

mary winding of the ignition coil makes the transistor

(TR1) conduct through the resistor (R) and forms the

primary circuit (indicated by dashed lines).

As the flywheel turns faster, the primary current

increases, and the terminal voltage of the circuit con-

sisting of the resistor (R) and the transistor (TR1)

increases. This increases the working voltage at the

connection of the series circuit (r1 + r2) connected in

parallel to the primary circuit. As the flywheel turns

further, the terminal voltage of the resistor (r2) in the

resistor circuit (r1 + r2) rises to the level of working

voltage of the transistor (TR2) when the ignition tim-

ing approaches the rated RPM, and, thus, the transistor

(TR2) is turned on. As a result, the base current of

(TR1) flowing through the resistor (R) is by-passed,

and the transistor (TR1) is turned off from the conduc-

tive state.

The current flowing through the primary winding (2)

is thus interrupted, and rapid change occurs in the

magnetic flux across the ignition coil. The result is a

high surge voltage in the secondary winding (3).

SPARK ADVANCE

CHARACTERISTIC

As noted above, the unit circuit detects a voltage and

makes switching to produce a high voltage required to

produce a spark. On the other hand, the wave form of

the voltage generated in the primary winding changes

as the flywheel turns.

The working voltage (VS) of the unit circuit is at level

A when the engine is started, but as the engine speed

increases, the wave form of the voltage changes and

advances to level B.

GEN-0009

Testing Electrical

Components

All tests of the engine electrical components should be

made using the digital Fluke Model 73 Multimeter

(p/n 0644-191). Replace any component that does not

have a test value within specifications.

NOTE: Whenever using a digital-style tester,

“open (infinite resistance)” denotes an overload
and the meter reading will be OL since the meter is
not calibrated to register resistance values of that
magnitude.

NOTE: Whenever testing switches, less than 1

ohm is desirable with the switch in the activated
position.

Troubleshooting

Ignition System

(120 cc Model)

1. Remove the spark plug and visually check its

condition. Replace if fouled. Adjust spark plug

gap to 0.7 mm (0.028 in.). Attach the high tension

lead to the spark plug and ground the plug on the

cylinder head.

NOTE: Make sure the emergency stop switch is

in the ON (UP) position, the ignition switch is in the
RUN position, and the tether cord is connected to
the tether switch.

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

spark is present, disconnect the main wiring

harness from the engine. Crank the engine over. If

spark is now present, the problem is either one or

more of the following items.

5-14

A. Defective ignition switch

B. Defective emergency stop switch

C. Defective wiring harness

D. Defective tether

Testing Main Wiring

Harness

(120 cc Model)

NOTE: The main wiring harness test can be

made using the Fluke Model 73 Multimeter (p/n
0644-191).

1. Disconnect the engine wires from the main wiring

harness.

2. At the main wiring harness engine connector,

connect the red tester lead to the violet wire; then

connect the black tester lead to the engine ground

(brown wire).

3. With the ignition switch in the RUN position, the

emergency stop switch in the ON position, and the

tether cord connected, the meter must read no

resistance. If the meter reads resistance,

disconnect the ignition switch from the main

wiring harness. If the meter now reads no

resistance, replace the ignition switch.

725-704A

4. If the meter continues to read resistance with the

ignition switch disconnected, disconnect the

emergency stop switch. If the meter now reads no

resistance, replace the emergency stop switch.

5. If the meter continues to read resistance with both

the ignition switch and the emergency stop switch

disconnected, disconnect the wires to the tether

switch. If the meter now reads no resistance,

replace the tether switch.

6. If the meter continues to read resistance with all

three switches disconnected, replace the main

wiring harness.

Troubleshooting

Ignition System

(EFI 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.

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 throttle

cable is 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 throttle

cable tension.

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

housing

C. Corroded or loose wire connection at the

throttle-control housing or main wiring harness

D. Defective ignition switch

E. Fouled spark plugs

F. Defective charge coil (#1 and/or #2)

G. Defective ignition timing sensor

H. Defective ECU or loose or corroded connection

in wiring harness

NOTE: To check these possible causes, proceed

to Testing Ignition System.

! CAUTION

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.

! CAUTION

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

Content .. 71 72 73 74 ..