Re: where is the air fuel mixture screw located on the carb?

I think it may be prudent to drill a hole in the side of the air breather cover.  A hole just large enough to allow a thin long reach screwdriver to reach the air mixture screw in question.  On my 826 (plastic tank) I have to remove the air breather box from the carb to turn the screw. A real bother.
A small hole would allow access to the screw.