Elusive Miss-fire

GMU was a good outing and the next Thursday I took the Trophy to the FIM Rally in Lithuania, while there a miss-fire gave me a continuous headache! A mate said most ignition problems are carb faults and most carb problems turn out to be ignition faults, so, so right.
Miss-firing started after filling up following a ride out in hot weather and over some rough roads, OK with small throttle openings in lower gears, bad stuttering at mid range, and smoother after 60 -65 mph.
Must be mucky fuel! so carbs off and check jets, clean out float bowls, clean spark plugs, check coil leads and plug leads and rebuild. No improvement! Maybe coils breaking down, it was very hot with some slow convoy riding.
Rode back home with fingers crossed (not easy). I thought I had solved the problem when I stopped to put waterproofs on just south of Warsaw when there were no lights on the panel when I wanted to restart, main fuse had corroded in the holder half of which had gone so a new fuse and a toothpick to wedge it in place, started but still miss-firing.
Back home I fitted 3 new coils- no better!! so today carbs off again and whoa ! the right hand needle broken 7 mm down from the spacer and the other two showing wear almost halfway through, hopefully new parts will cure the problem!
I have not heard of carb needles wearing through but after 120,000 miles everything is wearing out, the centre stand broke as I was about to start today's carb strip.
I will report on progress later.