rock-ola
If the spark plug looks good from normal riding, I think your jets are about right.
What's not right is the fact that adjusting the idle screws does nothing.
That would explain why the engine dies at idle speed.
The following is from Hitchcocks site and explains how to adjust these screws
"• Adjust the throttle stop screw so the engine runs at a fast tick-over, say about 20%
above the idle speed you wish to achieve
• Unscrew the pilot air screw to increase the engine speed to its fastest possible
• Gradually unscrew the throttle stop screw to reduce engine speed to the target idle
speed
• Again unscrew the pilot air screw to increase engine to the highest tick-over possible
• Finally, gradually unscrew the throttle stop screw to reduce engine speed to the correct
idle speed. (Usually this process carried out twice – as described – will be sufficient to
achieve a correct tick-over.)
NB – sequence: pilot air screw out = fast; throttle stop screw out = slow"
I highly recommend that you follow this link to that write up, paying special attention to the last part of it.
http://www.hitchcocksmotorcycles.com/pictures/content2/micarb_notes_-_a4.pdf(This is an PDF file so your computer will need to have Adobe installed to read it).