HELP!!! Intermitting loosing spark

[neiler46]

2007 ec 250 looses spark and cuts out after riding for around an hour. Anyone ever had this fault?. It starts after jiggling about with coil wire and unplugging and re plugging cdi connector. Dont no if this is a coinceidence but spark appears seems quite weak and it starts for another while..
Heres a bit of background info
Bike had a really bad missfire before after it got warm about 10/15minutes, so tried a friends coil and the wee black box thats bolted on to the coil..cured problem raced for 2.5 hour without a problem....so ordered a new coil
fitted it and ever since the bike stops every hour with no spark. Checked all wiring opened loom and checked all wires and connections / coil earth etc. Could that wee box bolted to the coil cause all this problem? Or is there just that many problems maybe it lies elsewhere??
I am trying to eliminate the fault quick as i have entered a race but its so time consuming as the bike will run for about an hour perfect.. any info would be a help thanks..

 

[Anders]

2007 ec 250 looses spark and cuts out after riding for around an hour. Anyone ever had this fault?. It starts after jiggling about with coil wire and unplugging and re plugging cdi connector. Dont no if this is a coinceidence but spark appears seems quite weak and it starts for another while..
Heres a bit of background info
Bike had a really bad missfire before after it got warm about 10/15minutes, so tried a friends coil and the wee black box thats bolted on to the coil..cured problem raced for 2.5 hour without a problem....so ordered a new coil
fitted it and ever since the bike stops every hour with no spark. Checked all wiring opened loom and checked all wires and connections / coil earth etc. Could that wee box bolted to the coil cause all this problem? Or is there just that many problems maybe it lies elsewhere??
I am trying to eliminate the fault quick as i have entered a race but its so time consuming as the bike will run for about an hour perfect.. any info would be a help thanks..

I had a similar problem with my 06 200. The problem was a bad ground connection at the coil, the frame was rusted at the place where the coil ground wire is connectd (at one of the coil screws).
But as you already have checked the coil grounding this is perhaps something different?

 

[Neil E.]

"wee box bolted to the coil" is likely your voltage regulator and has nothing to do with the operation of the ignition system.

 

[neiler46]

cheers yes already checked frame etc. ok good that rules voltage, regulator out.
just removed flywheel, outer insulation on stator is starting to crack and found a crack on the pickup coil casing.

 

[Neil E.]

Cracks that let in moisture can be a problem. As to the stator, only the "single winding" (exciter) is important. It's different from the others and powers the CDI. The flywheel sensing (impulse) coil that triggers the CDI can be tested for resistance value. The yellow and white wires are the lighting windings (nothing to do with ignition).

 

[neiler46]

I sent it off to get test and re wound but they say that its okay and it doesnt need anything.

 

[Caravan Monster]

I had similar with my 2006 ec 200. In the end it was coil > cdi wire. Story here:

http://www.gasgasrider.org/forum/showthread.php?t=21186