Another 2008 YZ450R No Spark

A friend bought this bike and has fallen in love with it.  Let's his 2012 500 EXC collect dust.  Last ride out, he went down on the kill button, picked it up, started right up and away we went......but not for long.  The bike went dead soldier so I told him to pull the kill button apart to isolate it as the potential problem.  Well, it's not the problem, or so he tells me.  So, it's now sitting in my garage as of this evening.  We have a riding trip 3/15 so I need to get him rolling quickly.  Hoping to obtain help diagnosing the issue and to get advice on upgrades.  Spent quite a bit of time searching here and GrayRacer513 seems to be the go to so I hope he can chime in.  If someone can give me the progression of parts to test first, how to do it, and what readings I should get, then I can help him not have to take it to a stealership.  Following is my stab at fist and subsequent steps.

 

Stator first: Seems this is the likely culprit often here on TT so I guess I need to run an ohms test on the stator, but don't have a manual and before you rap my knuckles, went to the link GrayRacer provided in another thread and cannot seem to get to a manual for the bike.  If someone can tell me how to check the stator and tell me what I should see on the meter, I am loosely qualified to turn it on and test with it if I have some "testing for idiots" guidance.  Advice - if it tests bad, would upgrading to a Baja Designs stator (or other) be better than an OEM replacement for both better quality and/or in the event he ever wants to power a light and/or a cooling fan?  I've read some about converting to the WR components to carry lilghts, etc.  Don't know if that is possible, true or internet lore?

 

If stator checks good, then pull flywheel to see if it has shelled itself.

 

If flywheel good, then how do I check the rectifier or the coil?  Again, testing for dummies is what I need.

 

Have also read here that using an '06 CDI might add some bottom end to this rig, although the owner loves it just like it is.  Is this an upgrade that is worthwhile?  Have read here that the CDI rarely fails and I don't know how to check it to begin with!

 

Sure appreciate any help.  Thanks guys.

I would check the wires going to the button as well, making sure they werent pinched some where.

Ive heard there are reliability issues with the stators that have been rewound for more power . My buddies 08 has about 240 hrs overall on the oem stator.

i found the secondary resistance on the link below. Wish i could be more help.

http://www.thumpertalk.com/topic/614547-08-yz450f-stator-test/

Edited by NW Briff

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