well its a world on it's own doing the tuning for the KTM....

dono about your German, but there is a very good web page K T M - S O M M E R they sale every thing you need, prepare Dakar bikes and so on...

well I try to explain... you got the sport-exhaust-system and the air-mash cover... well that's a start, but KTM don't tell you the right setup for the jets and needles.....
I guess you need the idle-jet 1.1 and a tuning needle !
at the end, in your case... ;o) you got the expensive parts already.....
the tuning needle part-no. [16254] for 12,90 Euro
consider to buy a extending fuel-mix screw part-no. [17410] for 20,50 Euro as well, that allow you to change the mix by hand without extra tools... ;o) it replaces the tiny STD adjusting screw, sticks out a lot and has a sort of T-piece handle on the end, very handy, all this together makes a big difference to your bike.
Ohh yes get your EPC-system deactivated if your bike is equipped with it... this EPC is only good to solve the emission law on the continent. to make it road leagle... sod it.... ;o)

to make it complete this posting getting a bit longer, sorry for that...

1st off all !!!!
forget altering any thing with a drill... !!!!
only use the right parts that are made for your carb or you may have to buy a new one and your fuel consumption is under no control !

OK here we go for all 640 Supermoto/Enduro/ADV - 1998-2002
------------------------------------------------------------------------------
Series setup:
idle jet STD: 1.2
main jet 142.5
needle STD: position 3rd from top / tuning needle: position 2 from top
air filter cover STD + STD-air-filter
exhaust STD

better setup with STD exhaust:
idle jet: 1.1
main jet 152.5 or 157.5
needle STD: position 3rd from top / tuning needle: position 2 from top
VA-air filter cover + STD-air-filter
exhaust STD

better setup with Sport exhaust:
idle jet: 1.1
main jet 157.5
needle STD: position 3rd from top / tuning needle: position 2 from top
VA-air filter cover + SM-air-filter
exhaust STD

better setup with Sport exhaust / ADV and travele setup:
idle jet: 1.1
main jet 155
needle STD: position 3rd from top / tuning needle: position 2 from top
VA-air filter cover + STD-air-filter
Sport exhaust

better setup with Sport exhaust aggressive setup::
idle jet: 1.1
main jet 157.5
needle STD: position 3rd from top / tuning needle: position 2 from top
VA-air filter cover + STD-air-filter
Sport exhaust

better setup with Sport exhaust racing setup::
idle jet: 1.1
main jet 162.5
needle STD: position 3rd from top / tuning needle: position 2 from top
VA-air filter cover + SuperMoto-air-filter element
Sport exhaust


right.... now for all 640 Enduro/ADV - 2003-2006
-------------------------------------------------------

Series setup:
idle jet STD: 1.2
main jet 152.5
needle STD: position 3rd from top / tuning needle: position 2 from top
air filter cover STD + STD-air-filter
exhaust STD

better setup with STD exhaust:
idle jet: 1.1
main jet 165 + STD-air-filter
or main jet 167.5 + SM-air-filter remove the snorkel
needle STD: position 3rd from top / tuning needle: position 2 from top
VA-air filter cover + STD-air-filter or SM-air-filter
exhaust STD

better setup with Sport / Akrapovic slip-on exhaust aggressive setup::
idle jet: 1.1
main jet 170+ SM-air-filter with or without snorkel removed
needle STD: position 3rd from top / tuning needle: position 2 from top
VA-air filter cover + STD-air-filter
Sport or Akrapovic slip-on exhaust and tuning db-eater


for all 640 SuperMoto - 2003-2006
---------------------------------------
there are more options to go for the SM Air-box, but as long you are riding 18" and 21" wheels and nobbly tires you don't want to know... it's a differed bike over all, only good for a short spin........ ;o)


----------------------------------------
well well, one tip if you try changing the idle jet... that one can be right a bastard, this little brass jet is hanging on to its carb and is tricky to remove, you may have to have a left-threaded bold remover or very hard edged spike handy in case the screw-slot from the jet comes off... as happened to me.... otherwise you are in trouble !
But one's you have changed the idle jet from STD 1.2 to the 1.1, you can start playing around with needles and main jets as you like to get the setup that match your need... ;o)
----------------------------------------

well a long post, but may help to find the right settings....
I ride a KTM 640 Enduro 2002 and use this settings and like it ;o)

aggressive fast throttle response, just nice...
idle jet: 1.1
main jet 162.5
tuning needle: position 2 from top
VA-air filter cover + SuperMoto-air-filter element + dustcover
SuperTrapp-Sport exhaust
with my 18L. fuel tank I can ride 340Km with this jetting, may not as good but I try to save up for the ADV tank....

I see you are in the UK, well I used to live near Oxford, no problems getting the parts ordered by KTM-Sommer in Germany, they do international deliveries.

have fun....
Spooky

__________________
The trouble is that he was talking in philosophy, but they were listening in gibberish.