The airplane was substantially damaged during a gear-up landing. The pilot reported that during cruise flight the "engine acted like it was going to quit." However, that lasted only about 3 seconds and the engine returned to running "smoothly" again, "just like nothing had happened." After the flight had traveled about another 10 miles, the same thing happened again. The pilot stated that at that point she elected to divert for a precautionary landing. She reported that when she attempted to lower the landing gear it would only partially extend. She noted: "I have mirrors on both wings to check the gear and the only one down was the nose wheel. The main gear was out of the cradle but not forward and locked." She noted that her attempts to use the emergency gear extension were not successful and she subsequently executed a gear up landing. The pilot and passenger were not injured. The gear locked in place once the airplane was jacked up after the emergency landing. A post accident inspection revealed a hydraulic leak located in the nose landing gear wheel well. The hydraulic reservoir had little or no fluid in it.