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08 ktm Xcw no spark

24K views 81 replies 8 participants last post by  prholcom  
#1 ·
I have 08 ktm xcw no spark replaced stator still no spark have 126 volts from cdi to coil coil testing was good cap good what else needs to be checked also pulser pick up good
 
#4 ·
I assume you have also fitted new spark plug?

Check all connectors and earthing.

Do you have same problem when kicking and also when trying to push start bike?
 
#5 ·
Are you testing spark while kicking or cranking with electric starter? If you test for spark while operating estart and find no spark, be sure to re test while kicking. Could be a simple solution if this is your test result. Report back with results and we will proceed.
 
#8 ·
Re read my previous post.
 
#14 ·
Are you testing with back yard test equipment like a multimeter/volt meter?
This stuff usually has to be bench tested.
How did you test the coil? Did you just do primary and secondary resistance?
If you have a peak voltage adapter for a multimeter you can check the primary coil voltage and that should be in between 150-200v.
 
#9 ·
Tested new stator values are border line bad at 65 degrees in shop i guess it possible i got s bad stator I was getting more voltage with oem bad stator than the new one by 15 to voltage
 
#10 ·
As I indicated and @augiedoggie also asked: How are you testing if you are getting spark? These bikes have a tendency to not start by pressing start button (no spark). If you have spark when you use the kick start and bike starts by using kick start and by push starting (find a nice hill and try to start bike down that one by jump on, start rolling down hill and put bike in 2'nd gear, release clutch and see what happens). If you can get the bike to start from kicking/push starting then there is a simple way to start the bike with using the start button... come back and tell us if bike started from kicking/push starting!
 
#13 ·
Many owners of these bikes have found that only way to get tem to start with starter motor is by tapping the kill switch quickly while pressing start button (remember to re-connect the kill switch first)
 
#24 ·
Usually you check primary coil voltage across the coil.
Cdi could fail from bad stator I do believe. Not sure if bad cdi would fail a new stator. (I suppose any severe load in an ignition system would fry other components)
If stator is starting to fail this early in the picture, there might be a problem with the flywheel.
I have no knowledge of an accurate testing procedure on a cdi without bench testing it.

I would be willing to learn if someone does have a procedure.
 
#18 ·
You're making progress. Tickling kill switch simulates trigger causing spark. If trigger wiring is ok you likely have defective CDI. I think your trigger is integrated into stator. You claim no spark with previous stator and coil secondary fires plug which proves ability to fire secondary. I'm fairly confident CDI is culprit. Post part number on module here on forum if possible. Will try to help
 
#19 ·
New stator is now failing ohm test after i got my shop up to 70 degrees went from 17.9 ohms to 18.3 exiter circut i also done some digging into factory stator found broken wire on exiter coil also pulsar pickup is separate from stator not built into stator itself it tested 100.1 ohm s
 
#27 ·
Here the correct CDI's for a 08 bike (based on these numbers I assume your bike is a 250xc-w):

Your CDI: 54839031100

2007/2008 bikes:
300 xc-w: 54839331200
250 xc-w: 54839031700
200 xc-w: 52339031900
250xc: 54839031600
250sx: 54839031800

2005/2006:
250 xc-w: 54839031400

2004 bikes have an older type of CDI that does not fit your bike.

Your motor number should start with 548 (same start number as the CDI). Based on the CDI number you have given us your bike is a 250xc-w. But it looks like your CDI has been superseeded. I am not convinced this is your issue. But once you start grasping straws (like we are doing now) perhaps the next step is to fit the correct CDI and hope for the best...

Here the CDI you need:
Cdi Unit 250 Exc 07/08 54839031700 $ 189.01 They are still available.
 
#33 ·
Hi Guys,

I have a 2010 250 xcw that I am also having a spark issue with. I have gotten the stator rewound as I was sure this was the problem. Since then I have swopped out the ignition coil with a other 250's one as well as the CDI. All with no spark. Funny thing is I am testing 15.5 Ohms on the plug which is correct. I cleaned all earthing wires to make sure it is earthing correctly. I have it with a local mechanic now who is trying to solve the problem but so far he also hasn't had any luck.

If anybody knows what it might be please give me a shout.
 
#34 ·
Wish I had the answer... We have only had 2 stroke SX KTM's. Their stator is simple and only has one winding (for the spark) the XC, XC-W etc have up to 3 windings on the stator. ( Ignition/spark, battery charging, lights).

Make sure you have the right winding connected to the right circuit!
Disconnect all but the spark/ignition supply from the stator. If you still have no spark the issue is in:
  • The stator
  • The connectors
  • The wiring
  • The coil
  • The spark plug cap
  • The spark plug
  • The CDI (In 12 years of racing MX we have had only one CDI die on us...)
And that is it...
 
#35 ·
Hi guys,


Wanted to share a great site for cross-referencing KTM parts. It can cut down on lots of research. Just plug in the part number in the search box and it will show you all the bikes that share the same parts. Sometimes is crazy to see how many bikes one part fits! https://www.ktmonlineparts.com.au/part/ktm/54839031700#content

Also, just wanted to share a story about lost spark and and the epiphany working on my Honda 400EX back in high school. I had stripped down my quad to powder coat the frame. Got it back and put back together, but it only ran for around 3-5 minutes and shut off. No lights, no spark, no neutral green light, nothing. Wait around 5 minutes and everything was back to normal, but when I started it again, the same thing happened. Stumped as could be. One day I was just going around touching stuff and I moved the exhaust and saw a spark from the bolt going to the frame, then AH HA! that's when I realized the stator was generating power but it was not a complete circuit because after powder coating the frame, I removed the ground for the motor. I ran a cable from the engine mount to bare metal and BAM, all is good! Was so proud of myself :)

My last no spark issue on the 2000 KTM 250EXC was a bad CDI box. I had a small crack in from the forks hitting it from a fall. Luckily I was riding local when it lost spark!
 
#36 ·
Well i still have not figured out why im not getting spark new stator new cdi tested cdi harness and coil coilwire plug cap could it be flywheel i can still bump the motor around with start button when i let off of it if its close to the pickup it will fire but not while cranking any ideas
 
#40 ·
Has anyone seen a voltage regulator short out and kill all grounds with positive volt while engine is cranking starter button pushed i have positive voltage on motor and frame soon as i let off the start button they go back to ground and ill get a spark when pick up coil is in position
 
#42 ·
That actually sounds more like earth leakage. Your bikes starter motor is trying to earth through the strongest earth point which should be the subframe via the earth terminal.
If it's trying to earth through the reg, it's probably fried the reg.
Poor earths and bad stators kill voltage regs.
I use to do a modification to all the carby 4 stroke ktm dirt bikes and that was a simple 5-6mm earth wire directly from the battery to one of the bolts holding the starter in. I have mentioned this mod 100's of times over the forum, but never heard back from anyone except maybe @ktmfreaky who I see was talking about the same modification in one of his posts.
The short earth strap is sh-thouse running onto the allow subframe. You either get a bad connection at the subframe or a bad connection at the bolts where the subframe bolts to the frame.
 
#41 ·
So the mechanic figured out what the problem was on my 250 xcw, it seems like my flywheel got damaged due to the stator that came loose. This caused a short and damaged my CDI(CDI is giving intermitted spark). So it seems like the big problem came from the flywheel. I bought flywheel, CDI and ignition coil off another bike, the parts will be here hopefully tomorrow. Will update you guys if all is good with the bike.

Quick question, the CDI I bought comes off a 300, would this cause any issues on my 250?
 
#43 ·
So the mechanic figured out what the problem was on my 250 xcw, it seems like my flywheel got damaged due to the stator that came loose. This caused a short and damaged my CDI(CDI is giving intermitted spark). So it seems like the big problem came from the flywheel. I bought flywheel, CDI and ignition coil off another bike, the parts will be here hopefully tomorrow. Will update you guys if all is good with the bike.

Quick question, the CDI I bought comes off a 300, would this cause any issues on my 250?
Thats a good question. I see the part numbers are different, but they probably use the same stator and coil. Not sure.
 
#50 ·
The pulsar signal is created for the CDI only. The pick-up-sensor that sits next to the flywheel either works or it does not work. You can measure the sensor with an ohm meter. If the reading is low then the sensor is ok. When the flywheel turns and activates the sensor the signal goes to the CDI that then does it's magic and send out the signal so that a spark is created.