no spark

20 replies to this topic
  • jeredlee

Posted August 11, 2008 - 08:51 PM


i have a 2004 yz 450 im not getting any spark. i put a new plug and coil timing is good and still nothing.i went through the eletrical system and it all looks good im stumped:confused: .any help would be awsome

  • desert-rat660

Posted August 11, 2008 - 08:57 PM


did u check the grounds? cdi unit?

  • desert-rat660

Posted August 11, 2008 - 09:04 PM


also check the kill switch, ive seen problems with them, a simple way to check it if u dont have an ohm meter is to unplug it. then see if u get spark

  • jeredlee

Posted August 11, 2008 - 09:13 PM


i have checked the kill switch and its good ill check the ground. were is the ground

  • desert-rat660

Posted August 11, 2008 - 10:02 PM


close to the cdi unit

  • bigred455

Posted August 12, 2008 - 06:40 AM


i have checked the kill switch and its good ill check the ground. were is the ground

Just unmount the kill switch and see if you get fire.

  • jeredlee

Posted August 12, 2008 - 10:56 AM


ok thanks ill try both and let you guys know

  • jeredlee

Posted August 12, 2008 - 07:07 PM


unpluged the kill switch and still no spark .didnt find the ground for the cdi you guys think the cdi box could be bad is there a way to check that

  • desert-rat660

Posted August 12, 2008 - 09:03 PM


easiest way is too swap it. is your pickup coil good?

  • shortburb

Posted August 13, 2008 - 05:15 AM


CDIs are not a common item to go bad.

Pull the ignition cover and check the flywheel/pickup.

My flywheel came apart and gave me a no spark symptom because the pickup ridge (I dont know what its really called) was no longer passing by the pickup therefore not initiating spark.

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  • jeredlee

Posted August 13, 2008 - 09:28 AM


how do you check the pick up coil

  • desert-rat660

Posted August 13, 2008 - 04:26 PM


u can ohm it out with a multimeter

  • rideout743

Posted August 28, 2008 - 07:48 AM


mine done the same thing! it is brokein now and i cant fegger out what is on the go!

i have a 04 yamaha yz450f and the other day it stoped working, it had no
spark from the spark plug so i got a new plug and now it has a good plug in it and it still wont start. i cant kick it over it wont start, i
cant pick it up by toeing it behind my dads truck. it has loads of compretion and i checked the timeimg chain and
stator and it is all good. when i to toe it behind dads truck it makes this low sound and is almost like
it wont take aney gass cause it dont realy move. aneyone have aney advice? i am realy stumped... :thumbsup::worthy:

  • jeredlee

Posted September 02, 2008 - 09:08 AM


i still cant find out whats wrong i think i might have to take it to the shop

  • desert-rat660

Posted September 02, 2008 - 10:33 AM


try disconnected the kill switch, if it fires up then u know the kill switch is bad

  • arnego2

Posted September 09, 2008 - 03:57 PM


Hi there
mine, a 2006 YZ450F went out quitely and after changing the plug without results we checked the stator which gives off energy so there are only a few items remaining. The CDI or the ignition coil, well the wiring too I suppose.

Lets hope that tomorrow I know more.

  • arnego2

Posted September 10, 2008 - 03:05 PM


Hello there
In my case it was the stator, well at least they have it here in the country. Soon I can :thumbsup: again on the YZ450F


  • jeredlee

Posted September 11, 2008 - 12:30 AM


what is the stator and were is it at i looked in manual and didnt see anything called that:confused:

  • arnego2

Posted September 11, 2008 - 05:00 AM


here you can see one: Posted Image its below the oil fill screw.


  • grayracer513

Posted September 11, 2008 - 05:20 AM


The manual refers to it as the magneto. Test is on page 6-8.

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