I use extractors all the time. The biggest problems are not drilling the hole in the center and not drilling the hole large enough. I always start with a small bit and work my way up to the largest bit possible. You want to use the largest extractor possible. Another problem is poor quality extractors. Chinese made extractors won't cut it.
So as of now, the primary flaps stay wide open when giving gas as there is no choke assembly on the passenger side of the carb. I just put the intake manifold and carb back on and can't get the car to run more than a few seconds before dying.