no spark

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

did u check the grounds? cdi unit?

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

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

close to the cdi unit

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.

ok thanks ill try both and let you guys know

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

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

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.

how do you check the pick up coil

u can ohm it out with a multimeter

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:

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

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

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.



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



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


here you can see one: S-8501-05_w100%20wr.jpg its below the oil fill screw.



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

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