What does the plug look like?
Run your finger around the inside of the exhaust outlet...carbon?
Is the choke cable too tight?
You need some slack there.
Carb screwed on tight.
Valves set correctly.
The idle jet(47.5) is a 'fuel' jet(not an air jet) so you richened it there with the bigger jet at and just off idle and you raised the needle...why did you do both?
Why did you install the 150 main?
That's a big jump too.
I would get the bike running right, then take it out on a flat stretch and see if it will go 100 mph with 16/42 gearing and stock jets. BTW did you enlarge the snorkle hole?
When it pulls cleanly from 2500 rpm and goes 100 mph that's all there is unless you change cams or get the hi flo head.
Be happy, it's faster than anything else in a drag race including the Honda 600XR racer with stock jets. It will run at 15 thousand feet with no jetting changes.
It is a big bike and weighs 400 lbs. It will do close to 50 mpg.
Running hot is a different problem with different reasons.
Check the oil for water contamination right away.
'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.
bmwktmbill screwed with this post 10-06-2012 at 12:12 AM