[Dan151]

Looking for some assistance with troubleshooting a no spark condition on my 2007 KVF750 Brute Force carbureted model. Took a gamble and purchased the ATV not running with unknown history. It only has 200 miles on it and overall in very good condition. When engaging the electric start in neutral (neutral light on) and in gear with the brake lever and foot brake engaged, the result is no spark at either cylinders.

Here is what I observed about the machine:
-New battery last year (multimeter reads 12.75 volts with a full charge)
-Electric starter cranks over smoothly and quickly
-All accessories are working; headlight, taillight, dash lights (including the neutral light)

Here are the troubleshooting facts so far:
-Started with the coils, multimeter reads roughly 6v key/power on and 7v while cranking at the power lead to both coils: Voltage drop or loss somewhere
-No ground buss bar on a 2007, checked harness plugs to fuse block and CDI, both clean with dielectric grease: OK
-Tested the rollover sensor, yield is 12v/5v at harness and 0.7v connected: OK
-Tested ignition switch, 6v at grey wire from switch and 6v at CDI plug: OK

What would be the next recommended test?

 

[NMKAWIERIDER]

I'm at a loss as to why you are showing lower then battery voltage on the coils, vehicle down sensor and ignition switch. Far as I know there is only one place the voltage is reduced and that's for control power for the actuator control system....which is somewhere is the 4.2-4.7 volt range. This sounds like a problem with the harness or..corroded connector under the fuse box. You are right in that 2007 does not have the buss connectors but...check anyway. Never know. Also, make sure no dielectric grease has gotten onto or into the pin or sward connectors of any connection. It's OK to have it around the outside.. but not on the connection itself.. Canned contact cleaner works well for blasting that out.

 

[Dan151]

I'm at a loss as to why you are showing lower then battery voltage on the coils, vehicle down sensor and ignition switch. Far as I know there is only one place the voltage is reduced and that's for control power for the actuator control system....which is somewhere is the 4.2-4.7 volt range. This sounds like a problem with the harness or..corroded connector under the fuse box. You are right in that 2007 does not have the buss connectors but...check anyway. Never know. Also, make sure no dielectric grease has gotten onto or into the pin or sward connectors of any connection. It's OK to have it around the outside.. but not on the connection itself.. Canned contact cleaner works well for blasting that out.

Thank you I will trying cleaning out all connections today and double check for a buss bar and the fuse block connection.

I am showing 12 volts at the correct wires to the vehicle down sensor and ignition switch, I was just pointing out the wires which should read lower voltages to indicate proper function to rule out the sensor and switch as a possible fault.

Is there a wiring schematic available anywhere for this machine outside of buying a service manual?

 

[NMKAWIERIDER]

Thank you I will trying cleaning out all connections today and double check for a buss bar and the fuse block connection.

I am showing 12 volts at the correct wires to the vehicle down sensor and ignition switch, I was just pointing out the wires which should read lower voltages to indicate proper function to rule out the sensor and switch as a possible fault.

Is there a wiring schematic available anywhere for this machine outside of buying a service manual?

I can PM you a download link to the my service manual which has the wiring diagram in it. Also test the CPS or pulse coil. And if the PO ever pulled the flywheel/rotor he may not have torqued it properly and it may have sheered the key. But do pull the retainer bolts from the fuse box, turn it over and pull the connector. Lots have had it corrode.

 

[Dan151]

I can PM you a download link to the my service manual which has the wiring diagram in it. Also test the CPS or pulse coil. And if the PO ever pulled the flywheel/rotor he may not have torqued it properly and it may have sheered the key. But do pull the retainer bolts from the fuse box, turn it over and pull the connector. Lots have had it corrode.

Started with the CPS following NMKAWIERIDER's recommendation, followed the procedure in the service manual and my Fluke 115 multimeter reads OPEN LOOP (OL) fault when testing resistance between the black/white and blue wires at the connector coming from the CPS. This leads me to believe the CPS has an open circuit and has failed. Will follow up when replacement part arrives and installed.

Have ordered Kawasaki Part #59026-0005 Pulsing Coil

 

[NMKAWIERIDER]

Started with the CPS following NMKAWIERIDER's recommendation, followed the procedure in the service manual and my Fluke 115 multimeter reads OPEN LOOP (OL) fault when testing resistance between the black/white and blue wires at the connector coming from the CPS. This leads me to believe the CPS has an open circuit and has failed. Will follow up when replacement part arrives and installed.

Have ordered Kawasaki Part #59026-0005 Pulsing Coil

Sounds like you found the problem already.

 

[Dan151]

Sounds like you found the problem already.

Hopefully so! Still perplexed by the low voltage at the coils. Is it possible that no signal from the CPS would create such a condition through the CDI?
Traced the blue/white and green/white wire directly from the coil to the CDI. Back probed and getting the same 6 volt reading at the connector to the CDI.

 

[NMKAWIERIDER]

I'll had always assumed the CDI provided the ground for charging and discharging the coils and the power supply was 12 volts from the AUX relay...or IGN system fuse but as I look at the wiring diagram, the BK/Y wire from each coil goes to a common chassis ground and the others, the BL/W and the G/W go straight to the CDI. So..that's what you get when you assume...lol. I'd like to know how others have reported 12 volts to the coils. And I am also wondering if a short or power spike could take out the CDI and the CPS/Pulse coil. Might have something going on somewhere.

 

[Dan151]

I'll had always assumed the CDI provided the ground for charging and discharging the coils and the power supply was 12 volts from the AUX relay...or IGN system fuse but as I look at the wiring diagram, the BK/Y wire from each coil goes to a common chassis ground and the others, the BL/W and the G/W go straight to the CDI. So..that's what you get when you assume...lol. I'd like to know how others have reported 12 volts to the coils. And I am also wondering if a short or power spike could take out the CDI and the CPS/Pulse coil. Might have something going on somewhere.

Thanks for staying with me on this journey! I followed the wire schematic as well, grounds lead me back to the "Engine Ground Terminal" which I cleaned and reattached.
I also checked for a buss bar, none found. Definitely an updated harness on this 2007, here is what it looks like:

 

[Dan151]

I'll had always assumed the CDI provided the ground for charging and discharging the coils and the power supply was 12 volts from the AUX relay...or IGN system fuse but as I look at the wiring diagram, the BK/Y wire from each coil goes to a common chassis ground and the others, the BL/W and the G/W go straight to the CDI. So..that's what you get when you assume...lol. I'd like to know how others have reported 12 volts to the coils. And I am also wondering if a short or power spike could take out the CDI and the CPS/Pulse coil. Might have something going on somewhere.

I'm starting to think you are on to something here. Only possible scenario that comes to mind is if the PO reversed polarity during an attempted jump start before replacing the battery not long before I bought it. In this scenario, would the CDI and CPS be so quick to fail or would it take out the resistor in the ignition switch and some fuses first? Neither the switch nor any of the fuses look to have been replaced recently.

I'm leaning towards ordering a second hand CDI with a return policy as I can't find any procedure for testing the CDI.

 

[NMKAWIERIDER]

I'm starting to think you are on to something here. Only possible scenario that comes to mind is if the PO reversed polarity during an attempted jump start before replacing the battery not long before I bought it. In this scenario, would the CDI and CPS be so quick to fail or would it take out the resistor in the ignition switch and some fuses first? Neither the switch nor any of the fuses look to have been replaced recently.

I'm leaning towards ordering a second hand CDI with a return policy as I can't find any procedure for testing the CDI.

I do know people have toasted their CDIs and ECUs by hooking up the battery backwards. The pulse coil being open says it got jolted to me as I usually see them with off-resistance readings..not open like that. I wouldn't buy another OE CDI. I would get one from Dynatek. Better and much cheaper. May need to go up on the pilot jets and shim the needles but the 6-8 extra HP is worth it.

 

[Dan151]

I do know people have toasted their CDIs and ECUs by hooking up the battery backwards. The pulse coil being open says it got jolted to me as I usually see them with off-resistance readings..not open like that. I wouldn't buy another OE CDI. I would get one from Dynatek. Better and much cheaper. May need to go up on the pilot jets and shim the needles but the 6-8 extra HP is worth it.

Just following up on the results. Installed a new Dynatek CDI and OEM crank position sensor today. Ignition voltage and spark conditions have both been resolved, the ATV fired right up and runs excellent.

Thank you very much NMKAWIERIDER for your help, so much valuable information to be learned on this forum

 

[NMKAWIERIDER]

Glad to hear she's up and running.