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.

Visit the ThumperTalk Store for the lowest prices on motorcycle / ATV parts and accessories - Guaranteed
  • 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.

Related Content



Dirt Bike   Make / Model Specific   Yamaha   YZ 400/426/450
  • Hot  30 replies

2016 YZ450 by CaptainKnobby

Dirt Bike   Dirt Bike Technical Forums   Suspension
  • Hot  59 replies
WR Camshaft Swap Info - last post by jamesm113

WR Camshaft Swap Info

  • 0 replies

Should I buy this bike? help....... by Numsa Hul

Dirt Bike   General Dirt Bike Forums   What bike should I buy?
  • * * * * *
  • 10 replies

Yamaha YZ450F 2017 by Chris.GVS

Yamaha YZ450F 2017
  • * * * * *
  • 1 review
  • Last review by Tommyk_55
  • On January 15, 2017

Join Our Community!

Even if you don't want to post, registered members get access to tools that make finding & following the good stuff easier.

If you enjoyed reading about "" here in the ThumperTalk archive, you'll LOVE our community. Come join ThumperTalk today!

The views and opinions expressed on this page are strictly those of the author, and have not been reviewed or approved by ThumperTalk.