You don't say what year your machine is?
I would drop the piston and inspect the bore for vertical scratches, if you see any the rings will need to be examined.
Me, I don't like that carbon and think it's heavy but I usually never overjet my engines(a raised needle is enough for me).
I bet your carb is over jetted or there is NO play in the choke actuation/cable. Just IMHO.
Clint and Gunner's opinions I respect on the carbon issue.
I swear I can feel an engine that is running 'fat'.
Do you have the two setting ignition for low octane fuel?
On a 40k trip you will need spares and tools and fresh suspension.
Like Gunner and Clint say, do the valve seals,cam followers and water pump.
I hope you figure out a way to turn the pin in the decomp.
We all need that.
I get excited just thinking about a 40k trip.
'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.