Am using correct spanner
Carb is an OS 40G fitted on the current OS 46AX as standard.
As I tighten the nut, the carb opening moves to wrong position. I.e. the arm is held in about the right position by the servo which is centered/neutral, but the torque to tighten the nut moves axle (?) itself, closing the carb...
Can't make it on Sunday, on family business sadly, but I am on holiday all next week so planning a good session all day Tuesday and/or Thursday.
Cheers!