the sleeve. Cylinder liner? Yes I have to agree. I try not to touch the liner if I can get away with it, but when I see a sharp edge I just have to knock it down. To maintain the throttle response it is advisable to keep the carb as small as possible. I have installed smaller carbs on some of my engines and found the throttle response improved greatly. I do however recomend polishing the "stack" and radiusing the intake to the carb somewhat. [8D]