Re: Air/Fuel Mixture screw head broken
Iv had this exact issue on my CBR F3, what i did was went on ebay and bought a spare single carb from a bike breakers and swapped it out, leaving me with a functioning carb set and bike.
Then came onto removing the screw... no amount of heat or penetrating fluid was helping so out came the air drill and compressor. Starting with a 2mm drill peice (which i snapped 3) i marked on the peice the maximun depth to go down into the hole and drill to said line, and then slowly went up drill peice sizes by 2mm until i was able to see a glimpse of the o-ring at the bottom and then started to pry the rest of the screw away from the thread walls. DO NOT go any lower than the o-ring, you will destroy the carb which is soft enough as it is! This was painstakenly slow even though the brass is very soft, go slow and take many breaks and make sure you mark on your drill peice the max depth. If you dont a steady hand then a pillar drill is also a very safe option. Total time, about 2 hours.