On September 14, 1997, at 0830 Alaska daylight time, a Piper PA-12 airplane, N7894H, sustained substantial damage when it nosed over during a precautionary landing on an 800 foot long gravel strip on the Moody River, about 20 miles east of Healy, Alaska. The airline transport certificated pilot was uninjured. The flight was conducted under 14 CFR Part 91 as a personal, local flight, and departed the Healy River Airport, Healy, at 0800. Visual meteorological conditions prevailed at the time of the accident, and no flight plan was filed. The pilot stated in an interview with the NTSB investigator, that during climb to cruise, the engine rpm began to decrease. He said that application of carburetor heat, and switching magnetos did not correct the problem. The pilot indicated that he was making a precautionary landing at an 800 foot landing strip, and that horses were on the strip. After flying over the horses, the airplane landed on the remaining strip and bounced. The pilot attempted to abort the landing, the landing gear contacted a berm, and the airplane nosed over. The NTSB investigator interviewed the persons who recovered the airplane. They reported an unknown quantity of water in the fuel, and worn fuel tank cap gaskets. The engine was tested at an engine shop in Anchorage, Alaska, and witnessed by an FAA airworthiness inspector. The engine produced a static rpm of 1,900 rpm, which is the minimum required by the type certificate. The inspector stated that cylinder compression was low, and the engine was "tired."