Hello, I have a us version '73 mgb with a weber 3630 (?) carb conversion. The car accelerates and cruises fine but when I slow down (more noticeable downhill) the car jibbs, or stutters or bucks, I'm not sure how to describe it exactly- it's not violent but noticable. It's not like the engine's cutting out or misfiring exactly. It brakes fine and steers fine so I'm open to suggestion. The carb is a two barrel with a single air screw, modeled after the simplest chevy carburetor, I think. Thanks for your time, even if it is yesterday where you are.