NO spark????

[machine]

I just bought a 04' KX5.
When I bought it they started it up fine.
Then I brought it home and started it up a few times great.
That was last Sat.

Now I put some new bars on it last night, and the thing wont start???
I've checked the kill swtich, and removed it.
I've checked all the wires with a continuity tester, and all check out good.
changed plugs, but still no spark?

Seems like there's just no spark from the coil, to the plug???

Any help would be great!!!

Thanks, Kev...

[gowen]

Hi Machine, make sure your connections are correct, also make sure the kill switch is completely disconnected and not grounded anywhere. Is there juice coming to the coil wire? I doubt the coil is bad, maybe the plug cap came loose? Maybe a bad plug. The big KX's are VERY known to foul plugs, due to lame jetting from the factory. Purchase a new plug and I'd go with a BR8 (or 9) EIX plug. But, if money is tight just try a new plug. You always have the option of grabbing the plug as you kick to see if any voltage is coming through.

I'm thinking it's the plug. Check that first. If not, it's your wiring or the coil is bad which is very unlikely.

[machine]

Gabe;
Thanks for the reply!
I can use all the help I can get!!!

I did change the plug, still no spark???

How do I check for power going to the coil???

I have un-puged, and re-pluged in all the wires too...
And I did remove the kill switch......

[gowen]

Hi Kev,

Hmm. Sounds wierd.. I'd start at the obvious. You tried the plug, so we know the plug is not the issue. You removed the kill switch, so that is not  sticking. Maybe make sure the wires are in correct order. It's pretty simple, black/white to black/white and so forth. Usally can't go backwards. Make sure water did not get in the connections and may have caused rusting.

Also, pull your flywheel cover, make sure it is not full of water. If you have a flywheel puller, pull the flywheel and make sure it is not rusted inside and check to see if any wires came loose.

Also, when you pull the flywheel cover check that the flywheel nut did not come loose, I've seen this happen. Also, check that the flywheel key did not snap.

Just a few things. Hopefully we can get this sorted out for you.

[machine]

Oh man I?m I depressed!  
The bike is new, never been ridden yet.
I bought it as a ?factory demo? as they called it.
It looks to be only ridden for about 10 minutes if that. It has the stock tires still on it.

I?ve never had the chance to ride it accept when I got it home, I rode it up and down my street twice.

The place where I bought it made it very clear that there are no warranties on MX bikes, they are sold as is???

But how do I check if there is power going to the coil???

[gowen]

I'm pretty d**n sure you can put a voltage meter in the wire feed to the coil and use a voltage meter and it should be putting something of the sorts to 5-10 volts? If nothing is coming out, you have a problem. Make sure you disconnect all wires, clean them, usally have rust or dirt in them, make sure all ground wires are properly installed and grounded.

Also, double check on the flywheel. Did it backfire or quit running on you? Anything funny at your last ride?

[machine]

It back fired the first time I started it, (a very small one ) but then I rode it twice up and down the street with out any problems?

[machine]

Can someone tell me how to check the coil, and CDI independently?
Sadly I don?t have a manual (Yet)
Thanks,
Kev?

[gowen]

Kev, I'll get out my manual this evening when I get off work. Try removing your flywheel cover and see if anything looks off. Maybe the flywheel loose, ect. ect.

[machine]

Ok, this is what I did tonight! (Or last night)

Got out the multimeter and did some checking.

I turrned the meter to AC/V (would not work in DC/V???)
Then I unhooked the CDI from the coil.
I hooked up the meter inline for the input into the coil.
I kicked over the bike and my reading was 3.89v
I then hooked back up the CDI to the coil, and kicked the bike over again.
With the ground on the frame, and the pos. in the end of the spark plug cap, I got a reading of .001/.000 at best...
Would this indicate a bad coil?
Is 3.89 a descent reading from my CDI???      

[Folke]

It back fired the first time I started it, (a very small one ) but then I rode it twice up and down the street with out any problems?

If it back fired, you must check the Reeds, i think you blow the reeds.

[machine]

It did it when the dealer started it too.
Not a real big one, just a little one just B 4 it started.
But after that it ran great?

Oh, I did check the flywheel too.
The bolt is tight, and the flywheel is on there solid!!!!


??

I'm starting to think it's the cooil?





If it back fired, you must check the Reeds, i think you blow the reeds.[/quote]

[machine]

But backfire or not, with or with out reeds it should stll have a spark!

[mikesmith]

Well I would check for a loose stator plate (behind flywheel) being it was back fireing it may be loose and now way out of time,should be on center mark of the 3 marks.If your getting some kind of reading I doubt its the igniter because that is go,no-go type of thing.Heres what my book list for readings,primary coil-.26-.36 ohms,secondary2.6-3.6 ohms.Stator BLK/WHT toBLK/YEL 153-230ohms,WHT/RD to BLK/YEL 7.9-11.9 ohms.You should get a manuel,if you cant find one for the newer 500 the book for the '93 on down will help you with almost every thing on your newer bike,hope this helps.

[machine]

Is the igniter the CDI, or the coil???
Thanks, it all helps.
I do have a manual on order...