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NO SPARK on '07 M8

PowderCrew

Well-known member
Premium Member
Dec 24, 2007
1,284
462
83
in the shadow of the Rubies, Nevada
History: Late last season I began getting a random "shutdown" on my M8. Was led to believe it was an issue with the throttle (TPS) adjustment. After shutdown, it would sit 5 or 10 min then fire back up and run again. I had to replace the ECU before all this began. Then the season ended before the problem could be solved. This season: First ride, rode 3+ hours before the random shutdown started again. Would sit 5 or 10 the run again for awhile. 2nd ride this season: Fired the sled at home to warm it up... fired it to unload, backed it down my ramp and she died on the ground. NO SPARK. Later that day, tried an ECU from another sled, no spark. So I start thinking Stator... BUT, MY ECU wont fire the other sled? No-one has EVER heard of the STATOR AND ECU failing at the SAME TIME? Any ideas out there?... The small plastic washers in the thumb throttle are good, as the adjustment seems to be as well. I have already (last season) unplugged the kill switch and just run off the key. Can find any wireing issue... EXCEPT that I cant find ANYWHERE where the motor is grounded to the chassis...
 

PowderCrew

Well-known member
Premium Member
Dec 24, 2007
1,284
462
83
in the shadow of the Rubies, Nevada
Bone stock... have the ohm ranges to start testing the stator, but like I was saying, IF it is the STATOR (or coil)...wouldnt my ECU have at least started the other M8? Anyone ever hear of a STATOR issue burning up the ECU as it fails? Or putting an ECU into a "sleep mode"?
 

m8magicandmystery

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Lifetime Membership
Jan 20, 2008
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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
(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
NOTE: To check these possible causes, proceed
to Testing Ignition System.
Testing Ignition System
(EFI Models)
NOTE: There must be free-play between the
throttle lever and the control housing.
MAIN WIRING AND SAFETY
SWITCHES
1. Check the wiring connections coming from the
ignition key and emergency stop switches. 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
coming from the engine stator assembly. 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 four-wire 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 four-wire 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 ECU. If the engine
starts, the problem is with the switches, main wiring
harness, or throttle cable free-play.
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 of 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 free-play 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. 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.


Electrical
Specifications
(800/1000 cc Models)
NOTE: The ignition system is a Normally Open Ignition (NOI).
* Main harness plugged in
Peak Voltage Tests were made at room temperature with the MaxiClips (p/n 0744-041), Fluke Model 73 Multimeter
(p/n 0644-191) set to the DC Volt scale, and the Peak Voltage Reading Adapter (p/n 0644-307). Also, the main
harness connectors must be unplugged (except on primary coil/CCU tests), the spark plugs removed and grounded,
and by pulling the recoil starter rope briskly.
NOTE: Lighting coil output is unregulated voltage.
Description Resistance Test
Test Value + Test Connections -
Ignition Coil
Primary
Secondary
0.24-0.36 ohm
5040-7560 ohms
black/white
high tension wire
white/blue
high tension wire
Charge Coil (1) 7.20-10.8 ohms black/red green/red
Charge Coil (2) 7.20-10.8 ohms brown/white green/red
Lighting Coil 0.08-0.12 ohms yellow yellow
Ignition Timing Sensor (1) 148-222 ohms blue/white brown/green
Ignition Timing Sensor (2) 142-222 ohms green/white brown/green
Injection Coil 15.2-22.8 ohms blue/white blue/white
Fuel Pump Coil 1.52-2.28 ohms orange orange
Spark-Plug Cap 4000-6000 ohms cap end cap end
Description Test Value + Test Connections -
Chassis Control Unit* 10-15 DC Volts red/blue (low power)
red/black (high power)
brown (low power)
black (high power)
Servomotor 12 DC Volts red/black (counterclockwise)
black/red (clockwise)
black/red (counterclockwise)
red/black (clockwise)
Low Oil-Light Sending Unit Less than 1 ohm (float end down) terminal terminal
Coolant Temperature Sensor Open
(coolant temperature lower than 190°F)
terminal ground
Up to 20 ohms
(coolant temperature higher than 230°F)
terminal ground
Coolant Temperature Warning Light Less than 10 ohms terminal terminal
Ignition Switch Less than 1 ohm (key in OFF position) terminal terminal
Description Peak Voltage Test + Test Connections -
MAG Primary Coil (Harness Side)* 125-137V orange/red orange/black
PTO Primary Coil (Harness Side)* 126-139V white/red white/black
Charge Coil (1) 13.6-14.8 black/red green/red
Charge Coil (2) 13.5-14.6 brown/white green/red
Lighting Coil 5.4-5.8V yellow yellow
Ignition Timing Sensor (1) 4.3V blue/white brown/green
Ignition Timing Sensor (2) 4.4V green/white brown/green
Injection Coil 12V blue/white blue/white
Fuel Pump Coil 12.3V orange orange
Lighting Coil 14.8-22.2V (@ 2000 RPM) yellow brown

Throttle Position
Sensor
(EFI Models)
NOTE: Ignition timing specifications are located
on the Electrical Specifications Chart in this section.
TESTING TPS
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 500 cc
is 12° ± 2° BTDC at 2000 RPM.
To quickly check TPS operation, measure the timing
according to the chart; then disconnect the TPS wiring
and recheck the timing. A system with a functioning
TPS will show a change in the timing. This is known
as “Fail-Safe Ignition Timing” and is built into the system
to protect the engine should the TPS fail. If this
change is not seen, the TPS may have failed and must
be checked.

If the ignition timing isn’t 12° ± 2° at 2000 RPM, the
TPS should be checked for proper adjustment using
the Throttle Position Sensor Adjustment Tool Kit (p/n
3639-891) and a digital voltmeter.
VERIFYING TPS ADJUSTMENT
TOOL
Before using the TPS adjustment tool, verify its battery
condition. The battery used in the tool is a 9-volt
battery. To check battery condition, use a digital volt/
ohmmeter set on DC volt scale. Test between the
adjustment tool black and red jacks. Insert the red lead
of the digital voltmeter into the red jack of the adjustment
tool and the black lead of the digital voltmeter
into the black jack of the adjustment tool. The green
power light of the analyzer should now be illuminated.
If voltage is found below 4.9 volts, replace the battery.
NOTE: The battery used in the tool is a 9-volt battery;
also, the Test Harness (p/n 0686-999) must be
plugged into the analyzer for testing voltage.
CHECKING TPS
NOTE: If the snowmobile is in warranty, breaking
the seal on the idle screw jam nut or the Phillipshead
screws on the TPS will void warranty. If the
TPS is tested out of specification, the throttle
assembly must be replaced.
NOTE: Before using the TPS adjustment tool,
verify its battery condition.
1. Using Throttle Position Sensor (TPS) Adjustment
Tool Kit (p/n 3639-891), connect its wiring harness
to the TPS. Connect the red and black digital
voltmeter leads to the white and black jacks of the
TPS adjustment tool.
2. Ensure that the throttle cable/control rod has the
proper amount of free-play.
3. With the throttle in the idle position, compare the
reading on the voltmeter to the chart. If the reading
is within prescribed specification, proceed to step 4.
4. Compress the throttle lever slowly to the full-open
position. The meter reading should show a smooth
rise in voltage all the way to the full-open throttle
position. If the voltage seems to be erratic or
doesn’t meet the prescribed specification, repeat
this procedure several times to confirm results.
5. If the full-open throttle voltage remains erratic or
out of specification; replace the throttle body
assembly.
6. If the TPS is within the prescribed specification,
disconnect the adjustment tool harness from the
TPS. Connect the snowmobile TPS harness to the
TPS.
NOTE: Before installing the TPS harness connector,
apply dielectric grease to the connector pins.
FAIL-SAFE IGNITION TIMING
Engines equipped with throttle position sensor have a
protective feature called “fail-safe” ignition timing
which prevents engine damage should the TPS fail. If
the TPS does fail, the engine will run normally at low
RPM but will run poorly at high RPM. This will allow
the operator to get the snowmobile to safety with little
or no engine damage.
NOTE: The engine will continue to operate this
way until the TPS is replaced.
Testing Electrical
Resistances
(800/1000 cc Models)
NOTE: Resistance tests of the engine electrical
components should be made using the Fluke Multimeter
only. Analog-style multitesters may not be
accurate enough to use in these critical tests.
Replace any component that does not have a test
value within specifications.
IGNITION COIL (Primary)
1. Disconnect the double wire plug from the ECU to
the ignition coil.
2. Set the selector in the OHMS position.
3. Connect the red meter lead to the black/white lead;
then connect the black meter lead to the white/blue
lead.
4. Ignition coil primary resistance must be between
0.24-0.36 ohm.
IGNITION COIL (Secondary)
1. Remove the spark-plug caps from the high tension
wires.
2. Set the selector in the OHMS position.
3. Connect the red meter lead to one high tension
wire; then connect the black meter lead to the
other high tension wire.
AK050D
4. Ignition coil secondary resistance must be between
5040-7560 ohms.
CHARGE COIL (1)
1. Disconnect the triple-wire plug from the main wiring
harness to the magneto.
2. Set the selector in the OHMS position.
3. Connect the red meter lead to the black/red wire in
the plug; then connect the black meter lead to the
green/red wire in the plug.
AK014
4. Charge coil (1) resistance must be between 7.20-
10.8 ohms.
CHARGE COIL (2)
1. Disconnect the triple-wire plug from the ECU to
the magneto.
2. Set the selector in the OHMS position.
3. Connect the red meter lead to the brown/white
wire in the plug; then connect the black meter lead
to the green/red wire in the plug
4. Charge coil (2) resistance must be between 7.20-
10.8 ohms.
LIGHTING COIL
1. Disconnect the main wiring harness from the
engine.
2. Set the selector in the OHMS position.
3. Connect the two meter leads to each of the yellow
leads in the connector from the engine.
4. Lighting coil resistance must be between 0.08-
0.12 ohm.
IGNITION TIMING SENSOR
1. Disconnect the two timing sensor connectors
(blue/white and brown/green - #1) and (green/
white and brown/green - #2) from the ECU.
2. Set the selector in the OHMS position; then connect
the meter leads to the sensor leads.
3. Ignition timing sensor resistance must be between
148-222 ohms.
SPARK-PLUG CAP
1. Remove the spark-plug caps from the high tension
wires.
2. Set the selector in the OHMS position.
3. In turn on each cap, touch a tester lead to each end
of the spark-plug cap.
B170
4. Spark-plug cap resistance must be between 4000-
6000 ohms.
IGNITION SWITCH
1. Remove the main wiring harness connectors from
the ignition switch.
2. Rotate the key to the OFF position.
3. The meter must read less than 1 ohm resistance
between the ignition switch terminals.
4. Rotate the key to the RUN position.
5. The meter must read OL (infinite resistance).
Peak Voltage Tests
(800/1000 cc Models)
NOTE: The following tests should be made using
the Fluke Model 73 Multimeter (p/n 0644-191) set to
the DC Volt scale with Peak Voltage Reading
Adapter (p/n 0644-307). For “engine running” test,
use MaxiClips (p/n 0744-041).
NOTE: Peak voltage test specifications are on the
Electrical Specifications (Individual) pages in this
section.
The Fluke Multimeter w/Adapter can perform the following
output tests.
A. Fuel Pump Coil
B. Injector Coil
C. Charge Coil (1) Output
D. Charge Coil (2) Output
E. Ignition Timing Sensor (1 and 2)
F. Primary Coil Output (MAG/PTO)
G. Lighting Coil Output
NOTE: Peak Voltage Tests (unless otherwise indicated)
were made with connectors unplugged
(except on primary coil test), spark plugs removed
and grounded, and by pulling the recoil starter
rope briskly.
FUEL PUMP COIL
1. Test between the two orange wires in the fourprong
connector from the stator.
2. Pull the recoil starter rope briskly. Meter reading
must be within specification.
INJECTOR COIL
1. Test between the two blue/white leads in the connector
harness from the stator plate.
2. Pull the recoil starter rope briskly. Meter reading
must be within specification.
CHARGE COIL (1) OUTPUT
1. Test between the black/red and green/red wires in
the triple-plug connector from the stator.
2. Pull the recoil starter rope briskly. Meter reading
must be within specification.
CHARGE COIL (2) OUTPUT
1. Test between the brown/white and green/red wires
in the triple-plug connector from the stator.
2. Pull the recoil starter rope briskly. Meter reading
must be within specification.
IGNITION TIMING SENSOR (1 and 2)
1. Test between the blue/white (1) or the green/white
(2) and brown/green wires in the connector from
the sensor.
2. Pull the recoil starter rope briskly. Meter reading
must be within specification.
PRIMARY COIL OUTPUT (MAG/PTO)
1. Connect the red meter lead to the orange/red wire
(MAG) or to the white/red wire (PTO); then connect
the black meter lead to the orange/black wire
(MAG) or to the white/black wire (PTO).
2. Pull the recoil starter rope briskly. Meter reading
must be within specification.
LIGHTING COIL OUTPUT
1. Connect the red meter lead to one yellow wire;
then connect the black meter lead to the other yellow
wire.
2. Pull the recoil starter rope briskly. Meter reading
must be within specification.
LIGHTING COIL OUTPUT (@ 2000
RPM)
1. Attach the red maxiclip to the yellow lead; then
attach the black maxiclip to the brown lead.
2. Connect the red meter lead to the red maxiclip;
then connect the black meter lead to the black
maxiclip.
3. With the rear of the snowmobile on a shielded
safety stand, run the engine at 2000 RPM.
4. Meter reading must be within specification
Chassis Control
Unit Voltage Test
(EFI Models)
NOTE: The following test should be made using
MaxiClips (p/n 0744-041) and the Fluke Model 73
Multimeter (p/n 0644-191) set to the DC Volt scale.
NOTE: Test specifications are on the Electrical
Specifications (individual) pages in this section.
NOTE: The CCU tests were made with the connectors
plugged in, spark plugs removed and
grounded, and by pulling the recoil starter rope
briskly.
LOW POWER
1. Connect the red maxiclip and meter lead to the
red/blue lead of the connector; then connect the
black maxiclip and meter lead to the black lead of
the connector.
2. Pull the recoil starter rope briskly.
3. Meter reading must be within specification.
Repeat test three times to confirm results.
HIGH POWER
1. Connect the red maxiclip and meter lead to the
red/black lead; then connect the black maxiclip
and meter lead to the black lead.
2. Pull the recoil starter rope briskly.
3. Meter reading must be within specification.
NOTE: Repeat this test three times to confirm
results.
 

m8magicandmystery

Well-known member
Lifetime Membership
Jan 20, 2008
7,786
3,724
113
Yukon
as well check wiring coming from taillights and loosen fuel tank and lift it up abit to check wires running under front of tank that go above brake rotor under tank to servo an reverse..
as well when tank is partial lifted pull coil wires forward from tank..real problem area there...
 
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