Its very common to have worn throttle shaft bores on the carby ,

This makes setting idle difficult as air is sucked in under high vacuum -
this is a good fix .

Solex Carb Throttle Shaft Bushings

Some of the series 1 carby rebuild kits come with a new throttle shaft (8mm diam.) . I've seen some bodies so worn, up to .060 of play in them .

Another article here with pics , different method

http://home.comcast.net/~rhodes/Tech...ng_Reaming.pdf



MIKE