KTM 640 - engine randomly dies

[Boon Booni]

Originally Posted by Queen of Spades

Update - got the switch back together last week with a light coat of di-electric grease on the internal connector plates (after first lightly cleaning them with a metal scotch brite pad).


Findings tonight:

Before turning the bike over, I connected my multimeter red terminal to the blue/white female connector, and the mm black terminal to the battery NEG post. I read 11.x volts, whether the key was on or not. (?)

I reconnected the blue/white connector at the coil, then started the bike up - it ran for maybe 10 seconds before dying. Confirmed no spark by using a timing induction light.

Disconnected blue/white at coil, and repeated first test above. This time it read ~50 mv or so. I also noticed a distinct whine coming from the area of the CDI (on the left side near the battery). This whine was not audible when I performed the first test.

Is this whining noise normal? Could it be related to the drop in voltage at the blue/white wire?

If you've got 12volts at the coil then our bikes have different ignition systems.


The whining noise sounds like "flyback" which Luke describes in the thread you linked as "very faint whining sound like a tube TV"

I see you responded to that thread, but the OP of the thread hasn't been back to ADV since 12-23-2010, so you might not get any reply.


Seems like Luke's reply is a good for some areas to check.

http://www.advrider.com/forums/showp...51&postcount=8