The kouba screw was tuned according to the included instructions; ended up being just over 2 turns out.

 

sounds a bit like water in the fuel. coming from a place with 400 inches of rain a year I deal with something that sounds similar... cross a river, suck in a splash, bike will run but when you try to put load on it sputters and stops....

 

Ran all new fuel through the system, stalling is still there. Is there a way to test the CDI ignitor box for proper operation?

 

Yup, put it on another same bike and see what happens. I blew a CDI recently and that's how I checked mine. My co-worker has an '07 and I diagnosed my toasted CDI by putting it on her bike.

There may be other ways, but none I'm aware of.

 

Same symptoms for me a few weeks ago.

My fuel filter was not seated correctly and a small piece of debris got caught in the main jet.

 

It turned out to be a clogged main jet. When I cleaned the jet before, I failed to notice the debris that were in the bottom of the bowl. Jet became clogged again, bike ran poorly.

 

Check the water in both rads the second rad has a bleed cap take if off when you fill it up my friend had the same problem he stripped the carb changed the CDI replaced the coil and lead plus plug AND THEN found there was no water in the second rad so the sensor was cutting the bike out - It may work it did for my friend