On June 7, 1994, at 1510 eastern daylight time, a Cessna 172, N3882L, collided with the ground and nosed over after the pilot experienced throttle control problems near Flowery Branch, Georgia. The personal flight operated under 14 CFR Part 91 with no flight plan filed. Visual weather conditions prevailed at the time of the accident. The airplane was substantially damaged, and the pilot and passenger were not injured. The flight departed Cumming, Georgia, at 1445 hours. According to the pilot, he and the passenger were sightseeing in the local flying area when the throttle failed to respond to inputs from the pilot. He further stated that engine rpm dropped to 1500 and he used the magneto switch to control engine power for the emergency landing. An examination of the engine assembly revealed that the throttle control linkage was completely disconnected from the carburetor. According to the pilot, the carburetor had been overhauled and installed on the engine two hours before this flight.