What is a slide carburetor?

Better known as a Flat-Slide carb. Some carbs have a butterfly throttle plate that opens and closes controlling the amount of air entering the engine. Others employ a round cylindrical (round slide) slide that does the same thing except it slides up and down instead of twisting open and closed. All high performance engines utilize a Flat-Slide in the carb that also slides up and down but the forces against the slide with all that extra air rushing through the carb , the slide resists sticking open or closed during operation.