I have found something which should make the process slightly less difficult:
http://www.bgm-tuning.com/shop/fuelair- ... hin-pwm38/
I have an idea that other firms also make a similar item, but the brand names escape me at the moment


The extended air screw as fitted. When fitted to the left-hand carb, the extended air screw only just clears the frame (by about 1-2mm!). The presence of the wiring loom still makes adjustment difficult, but it can just about be accomplished with the engine running (an auxiliary fuel supply is necessary because the normal fuel tank gets in the way!). If anyone is worried about frame clearance, the extended air screws can fairly easily be shortened before installation. I scribed a couple of short lines on the outer surface, as it is difficult to see the screw slot when installed.
Regards,
James