Narrative:

During a late evening return trip to my home airport; I stopped in [another airport] to wait out some thunderstorms that were passing through the area. I landed; shut down the airplane and called FSS on my phone to get a weather briefing for the remainder of my flight. I waited until the top of the hour when the new weather advisories were issued. With good VFR conditions for the route; I conducted a quick preflight and prepared to depart for [home].during the start checklist I gave the engine a pump of primer. While cranking the engine for start there were no signs of it firing or turning over. I waited about 30 seconds and tried again without priming; as the engine was still warm from the prior flight. Again; there were no signs that the engine would start. I then waited over a minute; and leaned the mixture and advanced the throttle before another attempt; suspecting that the engine may have been flooded. I cranked again and the engine sounded like it was going to start but never did.shortly after this and while awaiting another try; I noticed some smoke near the front of the cowling. Although I couldn't see any visible flames; I pulled out the mixture control and cranked the engine with the throttle full open as a precaution for an engine fire. I also moved the fuel shutoff up to the closed position as best as I could; although it appeared jammed and was extremely difficult to turn. When I got out of the airplane I noticed a small fire burning on the nose wheel. I went back to the cabin to search for a fire extinguisher but couldn't find one. Upon going back to the front of the airplane I noticed that there was also a small fire in the air inlet/filter. My reaction at this point was to call 911 for help. I removed a few personal belongings and assured that the switches were off.a police officer arrived in about 5 minutes and handed me a fire extinguisher from his vehicle; which ended up not spraying as it needed to be recharged. The fire department arrived in the next 5 minutes and the fire was still burning in the engine cowling. While they were preparing to put out the fire; the engine started to crank for no apparent reason; which seemed strange since everything had been turned off. This happened for almost a minute with the engine never actually starting; until they sprayed the cowling with water to extinguish the fire.considerations- considering the earlier weather at my destination; it was a non-rushed evening and I wasn't hurried.- I had started the airplane three other times that day. During a prior attempt (cold) I remembered that the engine took a little more cranking to start than similar airplanes I'd flown.- the first signs of the fire (smoke) were subtle. Had I noticed sooner; I may have executed the engine fire during start items sooner to better contain the fire.

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Original NASA ASRS Text

Title: C150 pilot reported he experienced an engine fire when he tried to restart the hot engine.

Narrative: During a late evening return trip to my home airport; I stopped in [another airport] to wait out some thunderstorms that were passing through the area. I landed; shut down the airplane and called FSS on my phone to get a weather briefing for the remainder of my flight. I waited until the top of the hour when the new weather advisories were issued. With good VFR conditions for the route; I conducted a quick preflight and prepared to depart for [home].During the start checklist I gave the engine a pump of primer. While cranking the engine for start there were no signs of it firing or turning over. I waited about 30 seconds and tried again without priming; as the engine was still warm from the prior flight. Again; there were no signs that the engine would start. I then waited over a minute; and leaned the mixture and advanced the throttle before another attempt; suspecting that the engine may have been flooded. I cranked again and the engine sounded like it was going to start but never did.Shortly after this and while awaiting another try; I noticed some smoke near the front of the cowling. Although I couldn't see any visible flames; I pulled out the mixture control and cranked the engine with the throttle full open as a precaution for an engine fire. I also moved the fuel shutoff up to the closed position as best as I could; although it appeared jammed and was extremely difficult to turn. When I got out of the airplane I noticed a small fire burning on the nose wheel. I went back to the cabin to search for a fire extinguisher but couldn't find one. Upon going back to the front of the airplane I noticed that there was also a small fire in the air inlet/filter. My reaction at this point was to call 911 for help. I removed a few personal belongings and assured that the switches were off.A police officer arrived in about 5 minutes and handed me a fire extinguisher from his vehicle; which ended up not spraying as it needed to be recharged. The fire department arrived in the next 5 minutes and the fire was still burning in the engine cowling. While they were preparing to put out the fire; the engine started to crank for no apparent reason; which seemed strange since everything had been turned off. This happened for almost a minute with the engine never actually starting; until they sprayed the cowling with water to extinguish the fire.Considerations- Considering the earlier weather at my destination; it was a non-rushed evening and I wasn't hurried.- I had started the airplane three other times that day. During a prior attempt (cold) I remembered that the engine took a little more cranking to start than similar airplanes I'd flown.- The first signs of the fire (smoke) were subtle. Had I noticed sooner; I may have executed the engine fire during start items sooner to better contain the fire.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.