Narrative:

I was over departure end of runway when engine lost power and was running very rough. Coincidentally; at that point; tower told me to change to departure; but I said I needed to stay with tower and return to land. I entered a right down wind to [departure] runway; and we agreed I would land on [another runway] since I was already in a right base to the closer runway. Tower asked if I wanted to [advise ATC]. Since engine was still very rough and I had no idea what it would do next; I answered that yes; I was [advising]. Tower cleared me to land; and I did. Crash trucks arrived; and their crews assured me that there was no fire; no smoke and no leaking fluids. I started the engine again; taxied to the ramp; tied the airplane down and left it there until I could get a qualified mechanic to look at the engine. An FAA licensed mechanic met me at the airplane [three days after]; and after several tests; disassembled the left carburetor and discovered a severely clogged jet. He cleaned the jet; reassembled the carb and engine ran normally. I flew it back to home airport that afternoon.

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Original NASA ASRS Text

Title: Pilot of light sport aircraft reported engine problems after takeoff resulted in a return to the field.

Narrative: I was over departure end of runway when engine lost power and was running VERY rough. Coincidentally; at that point; Tower told me to change to Departure; but I said I needed to stay with Tower and return to land. I entered a right down wind to [departure] runway; and we agreed I would land on [another runway] since I was already in a right base to the closer runway. Tower asked if I wanted to [advise ATC]. Since engine was still VERY rough and I had no idea what it would do next; I answered that yes; I was [advising]. Tower cleared me to land; and I did. Crash trucks arrived; and their crews assured me that there was no fire; no smoke and no leaking fluids. I started the engine again; taxied to the ramp; tied the airplane down and left it there until I could get a qualified mechanic to look at the engine. An FAA licensed mechanic met me at the airplane [three days after]; and after several tests; disassembled the left carburetor and discovered a severely clogged jet. He cleaned the jet; reassembled the carb and engine ran normally. I flew it back to home airport that afternoon.

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.