ADVrider

Go Back   ADVrider > Bikes > Thumpers
User Name
Password
Register Inmates Photos Site Rules Search Today's Posts Mark Forums Read

Reply
 
Thread Tools Search this Thread Display Modes
Old 12-04-2012, 06:24 PM   #1
Queen of Spades OP
tall drink of water
 
Queen of Spades's Avatar
 
Joined: Mar 2009
Location: Decatur, GA
Oddometer: 826
Eh? KTM 640 - engine randomly dies

Started a couple weeks ago on the way home. The bike was properly warmed up and out of nowhere - died at a traffic light. A couple presses of the Magic Button and she fired up and drove home the rest of the way.

Yesterday I went for a play ride and the bike again stalled just as I was getting onto 285. Like before a couple stabs at the MB got things going again. The bike ran fine the rest of the afternoon - logged about 40 miles, 10 of that woods trails including a couple creek crossings. Not a whimper.

Obligatory trail pic:


This morning on my way in to work, the bike stalled again after coming to a stop sign. This time it was a little harder to get going. A couple minutes later it finally lit up, and I rode the rest of the way to the office without a problem.

Tonight, again at a red light, the bike inexplicably died. I pushed to the side of the road and continued trying to get it to light up - nothing doing. I had no tools so I couldn't do any troubleshooting. I paged a taxi and after going home to get my pickup, the bike started right up.

Loaded it up and when I got home, I unloaded and again started it up - it ran fine for about 30 seconds, then died. Wouldn't start again.

WTF is going on?
__________________
'99 KTM 640 LC4 Enduro http://www.youtube.com/watch?v=fifXkDQpda4 (January 2014 snow ride)
Queen of Spades is offline   Reply With Quote
Old 12-04-2012, 06:58 PM   #2
AustinJake
TE450-KLE-FXDWG
 
AustinJake's Avatar
 
Joined: Aug 2010
Location: Austin, TX
Oddometer: 3,655
I had the same problem on my Husky, intermittent dying and restarting, also some cutting out before dying. Turned out to be a rubbed raw wire, and this wire just happened to be connected to the fuel pump, the fuel injector AND the coil!

__________________
____________________________________
Get fit. Stay safe. Enjoy life. Learn something to help someone in need.
AustinJake is offline   Reply With Quote
Old 12-04-2012, 09:49 PM   #3
bmwktmbill
Traveler
 
Joined: Jul 2005
Location: Traveler
Oddometer: 4,788
I would check the ground connection at the battery for tightness, then the positive connection.
Wiggle the main fuse, make sure the contacts are tight.

Do you have issues with the dash lights?
If you do I would consider the ignition switch, not a bad idea to unplug/plug that connection to the main wiring loom.

Do you have a kickstand switch?

bill
__________________
'02 KTM 640 Adventure-lowered
"On the road there are no special cases."
Cormack McCarthy-The Crossing

The faster it goes the faster it breaks.
And high performance=high maintenance.
Bill Shockley
bmwktmbill is offline   Reply With Quote
Old 12-04-2012, 10:40 PM   #4
Steveman
Gnarly Adventurer
 
Steveman's Avatar
 
Joined: Sep 2011
Location: Austria
Oddometer: 471
First two things to check before you look for problems with wires and/or terminals is:

a) does she get fuel
b) do you have a powerful spark

You have exactly three possibilities, no/not enough fuel (a), no/not good enough spark (b) or both (a+b).

As soon as you have found out if it is a fuel or electrical problem (no spark) you can go and look for the cause.

Good luck
Steve
Steveman is offline   Reply With Quote
Old 12-05-2012, 04:56 AM   #5
Queen of Spades OP
tall drink of water
 
Queen of Spades's Avatar
 
Joined: Mar 2009
Location: Decatur, GA
Oddometer: 826
Quote:
Originally Posted by bmwktmbill View Post
I would check the ground connection at the battery for tightness, then the positive connection.
Wiggle the main fuse, make sure the contacts are tight.

Do you have issues with the dash lights?
If you do I would consider the ignition switch, not a bad idea to unplug/plug that connection to the main wiring loom.

Do you have a kickstand switch?

bill
Last winter I lost all electrical and eventually traced it back to a connector with two wires that looked scored/burned. A few weeks ago I had some trouble with the headlight failing due to a loose fuse connection.

I wouldn't be surprised if something else is wonky with the wiring.
__________________
'99 KTM 640 LC4 Enduro http://www.youtube.com/watch?v=fifXkDQpda4 (January 2014 snow ride)
Queen of Spades is offline   Reply With Quote
Old 12-05-2012, 10:35 AM   #6
Betelgeuse
Don't Panic
 
Betelgeuse's Avatar
 
Joined: Apr 2005
Location: Central NH
Oddometer: 214
Ignition Switch

X2 from bmwktmbill. Check the wiring under the ignition switch by wiggling the loom leading up to the switch itself. I've had a wire break off up there twice. You can't see if it's broken unless you take it off and look for it.
Good luck.
__________________
640 Adventure
CRF250X
'72 Ossa MAR
Betelgeuse is offline   Reply With Quote
Old 12-05-2012, 10:46 AM   #7
Grreatdog
Beastly Adventurer
 
Grreatdog's Avatar
 
Joined: Apr 2007
Location: Annapolis, MD
Oddometer: 9,783
Anytime a bike acts like that the first thing I do is ride around with the gas cap loose to see if it is a venting issue.
__________________
640E, MXC200, XT200
Grreatdog is offline   Reply With Quote
Old 12-05-2012, 10:50 AM   #8
motomark39
I reckon so
 
motomark39's Avatar
 
Joined: Feb 2007
Location: Odenville, Alabama
Oddometer: 1,076
ignition switch

I have had two ignition swithches go bad on two different 640s
__________________
2013 HusabergTE300
2000 BMW R1100RT
motomark39 is offline   Reply With Quote
Old 12-05-2012, 12:14 PM   #9
clintnz
Trans-Global Chook Chaser
 
clintnz's Avatar
 
Joined: May 2004
Location: Rotoiti, New Zealand
Oddometer: 3,299
If all the wires behind the dash & the sidestand switch check out ok also have a look at the wires coming out of the igniter box under the RH sidecover. I had some of these rub through against each other which caused some intermittent cutting out. It was hard to see anything was wrong until the wires were moved & inspected closely.

Cheers
Clint
__________________
'03 KTM 640 LC4 Enduro

The wilderness, the desert - why are they not crowded
.................................................. .....with pilgrims?
clintnz is offline   Reply With Quote
Old 12-05-2012, 12:57 PM   #10
MORT666
Gnarly Adventurer
 
MORT666's Avatar
 
Joined: Aug 2009
Location: U.K
Oddometer: 214
Change the plug cap.
MORT666 is offline   Reply With Quote
Old 12-05-2012, 02:49 PM   #11
Queen of Spades OP
tall drink of water
 
Queen of Spades's Avatar
 
Joined: Mar 2009
Location: Decatur, GA
Oddometer: 826
Ya'll assign too much homework!!!
__________________
'99 KTM 640 LC4 Enduro http://www.youtube.com/watch?v=fifXkDQpda4 (January 2014 snow ride)
Queen of Spades is offline   Reply With Quote
Old 12-05-2012, 07:37 PM   #12
bmwktmbill
Traveler
 
Joined: Jul 2005
Location: Traveler
Oddometer: 4,788
How right...change the plug too.
bill
__________________
'02 KTM 640 Adventure-lowered
"On the road there are no special cases."
Cormack McCarthy-The Crossing

The faster it goes the faster it breaks.
And high performance=high maintenance.
Bill Shockley
bmwktmbill is offline   Reply With Quote
Old 12-07-2012, 10:51 AM   #13
biensur22
Gnarly Adventurer
 
biensur22's Avatar
 
Joined: Oct 2011
Location: San Diego, CA
Oddometer: 179
This was happening on my 620 adventure too. After popping the plug and discovering I had no spark, I pulled the whole fairing and electrical compoents from the front end to limit the variables. Bike fired right up and idled smoothly. Took the fairing.electronics on the bench and discovered various frayed powered wires. I cleaned them up and plugged everything back in. Haven't had any problems yet.

So here's the break down:

1. Check that you have consistent spark (pull plug, attach cap, ground it against the frame, hit the starter - should see a blue spark)

If no spark, check your electrical as discussed. If you have spark:

2. Check fuel supply. Make sure your starter and idle jets are clean/clear, and check your float height. Clean/replace fuel lines, filter, etc.
biensur22 is offline   Reply With Quote
Old 12-07-2012, 01:19 PM   #14
SRG
SRG
 
SRG's Avatar
 
Joined: Nov 2004
Location: Charlottesville, Virginia USA
Oddometer: 1,138
There is a vacuum line that runs from the fuel pump to the carb. If it gets kinked the bike will die.

May not be your problem, but it's easy to check.
__________________
Lazy Traveler
SRG is offline   Reply With Quote
Old 01-20-2013, 02:23 PM   #15
Queen of Spades OP
tall drink of water
 
Queen of Spades's Avatar
 
Joined: Mar 2009
Location: Decatur, GA
Oddometer: 826
Update -- finally ventured out into the cold, cold shop to peel off the pumpkin's seat & plastic. Upon removing the seat I saw two red/yellow wires dangling as though they may have been connected together.. on closer inspection it looks like they were plugged into a white connector, and worked loose. A few inches away from the now loose end, there is a fuse holder (fuse OK).

I can't find the exact yellow/red wire in my diagram, though. Did KTM ever publish a color wiring diagram for the LC4 640 models? I cannot find a fuse holder with yellow/red wire on my diagram.
__________________
'99 KTM 640 LC4 Enduro http://www.youtube.com/watch?v=fifXkDQpda4 (January 2014 snow ride)
Queen of Spades is offline   Reply With Quote
Reply

Share

Thread Tools Search this Thread
Search this Thread:

.
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On

Forum Jump


Times are GMT -7.   It's 09:06 AM.


Powered by vBulletin® Version 3.8.5
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Copyright ADVrider 2011-2014