KTM 640 - engine randomly dies

Gunner, is the stator in oil? Do I need to drain it first?

And this from bigtators:

There is not much oil in the stator chamber... I usually lay the bike over a bit propping it up at 45 degrees with a couple of blocks, then no oil leaks out...

It is possible that in your poking and prodding with the tester you may of fried your CDI , hopefully not...

Never tested resistance or voltage on any of the CDI wires. The symptoms haven't changed before I even did any of that.

Sounds like a possibility... Though $201.55 is quite a bit of a guess...

EDIT.. $181.58 for your bike. Neither one as bad as I would have thought actually.

If that is what's going on I'll be getting two of them, one to keep as a spare.

Next thing I will check out is the start/stop switch.

Where did you find a CDI for $181.58?

I'm showing KTMWorld listing it as
<table class="parts_list"><tbody><tr class="parts_list_odd_row"><td class="parts_list_cell" align="left" nowrap="nowrap" valign="middle">58439031000</td> <td class="parts_list_cell" align="left" valign="middle"> DIGITAL BOX CDI</td><td class="parts_list_cell" align="center" nowrap="nowrap" valign="middle">
</td> <td class="parts_list_cell" align="Right" nowrap="nowrap" valign="middle">
</td> <td class="parts_list_cell" align="Right" nowrap="nowrap" valign="middle">359.82 </td></tr></tbody></table>

Found it on KTM Parts House at $182

<table id="PartsList" border="0" cellspacing="0"><tbody><tr><td class="li" style="width:286px;" align="left" valign="top">DIGITALBX CDI CB7459 95ROZ'99
58439031200 (replaces 58439031000) </td><td class="li" style="width:42px;" align="center" valign="top">1</td><td class="li" style="width:52px;" align="center" valign="top">
</td><td class="li" style="width:64px;" align="center" valign="top">$181.58</td></tr></tbody></table>

Will hold off ordering until I am positive nothing else is causing the problem.

I'm beginning to wonder if the loose wires from reply #17 this thread didn't cause the CDI to malfunction.

Yep, that's the place. I've ordered $300 in bits a pieces from them over the last few months.

Update:
I placed an order for a replacement/spare CDI with KTM Parts House. I haven't ruled out other problems (see further below) but ran into trouble getting a headlight switch last year (discontinued for the 99 model). This machine is getting some age on it, and I don't want to run into a similar problem with a CDI. Also ordered a spare start/stop switch for the same reason, since I've read that part has been associated with failures on some LC4's. I should probably get a spare pulsar coil for the same reason.

Having said all that, check the response from KTMPartshouse regarding updated CDI part number and price:

I ordered two new 6 pin Molex connectors to fix some existing wiring hacks from previous owner (looks like they hooked up a different headlight at some point, then put the stocker back on). Got the .093 molex pin tool, too.

While I have the top end exposed I'm going to check valve clearances and adjust as needed. Motion Pro feeler gauges arrived last week. Have two cover gaskets on the way.


Next Steps:
Plan is to check my current stop/stop switch for resistance and make sure that is working properly.
Will pull the generator cover (per post above) and make sure there isn't any damage there.
Finally, will go through the existing wiring with a fine tooth comb, organizing and zip-tying/taping where needed.

Trouble with a Molex .093 connector. I removed the male pins out with a .093 extraction tool, but the female pins appear to be the same size as the tool I have.

Anyone know what size tool I need to get the female pins out?

EDIT: Called Molex directly, they say that the extraction tool should remove both male and female pins in the connector housings. The tool I bought was a cheapy, they recommended their own tool, which I've since ordered.

Hey Queen, any updates on this?

Bike in still in pieces. Threw back out working in my garden a couple weeks ago. Pain city.

Spades,
Sympathy and motorcycle prayers.
I'm a nurse so consider the source of this.
I hate back pain, it's a set up for disaster.
It is usually treated incorrectly.

So an old motorcyclist's advice.
Muscle relaxers X 5-7 days(Valium or Flexeril(your doctor will resist this idea unless he is experienced)), also concurrent with the muscle relaxers, Aleve(double dose X 2 days, then a regular dose for a week every 4-6 hours. Walk a block after one week extending the distance until you can walk 3 miles.

No narcotics.
Walk!

How do I know?
I treated many pain sufferers.
I have a broken and healed back and a blown R. knee.
I could only walk one block 5 years ago. My back was fragile. I had broke my pelvis riding in Bolivia and also got hit by a Lexus on the Mex border, Lymes Disease hit me hard in the midst of all that.

Once the pain is gone either hit the gym or do stretching exercises in your home.
START SLOWLY.

I skiid 34 miles in the Bierkiebiner race a couple of weeks ago.
I am 67 years old.

Fix that motorcycle, pain is a complex issue.
The expression of physical pain does not always identify the underlying problem.

Your mindbody is about a complex as your KTM.
It may resist.
bill

Thanks for that Bill - appreciate the encouragement & prayer.

Is it bad to lean into the pain? I kinda can't avoid it when going from sitting to standing or vice-versa. But is it good to stretch into it, to loosen it up?

No stretching until pain is gone or mostly gone. Ice and anti-inflammatories when it first gets hurt for 48 hrs, off and on. I keep it on as long as I can take it. 20 minutes I believe is the standard? Then heat and rest and anti inflammatories. Of course as much rest as possible until healed. Then you want to do stretching and strengthening to prevent this from happening again. I still work on my motorcycles if the pain isnt too much. Been dealing with a bad back since i hurt it in football back in 88. yoga, lots of core exercises and an herb called turmeric (a natural herb that helps with inflammation in the body). My back is as good as it can be. Still hurts all the time, just not the muscle spasm kind of hurt any more. When your back is truly out. You cant do chit. Working out for 30+ years. I dont know everything but I have learned a lot.

+10, be gentle with yourself.
b

Anyone know what I should be showing for voltage at the rear brake light socket? There are two power leads and a ground. One power lead is for the always-on light (dimmer), and the other for when the brake circuit is engaged. I'm showing that both have power -- one ~3v the other ~12v - with no brake applied. When brake is applied, both terminals show ~12v. Is this how it's supposed to be?

Should be 0 and 12 with with the brake off. That 3volts is probably an induced voltage from that wire running up against other wires that are carrying current.

Rear brake switch isn't working. Only the front lever/switch gives me a brighter brake light. Looks like something else I need to replace.

Put a continuity tester on the switch and see if you are getting any continuity when the brake pedal is pressed.