Narrative:

Summary: en route lost 200-250 RPM. Landed at airport nearby. Misdiagnosed problem. I took from from bed on a hot on a hot, humid, hazy day in an small aircraft with a 6 cylinder engine. I adjusted the mixture about 10 mi west of bed, using the newly replaced egt. Shortly thereafter I noticed a 200-250 RPM loss, and the engine did not sound normal. However, since I just had new mufflers installed, I was not sure the engine sounded wrong. I was not used to the new sound. Loss of RPM was like carburetor ice, but carburetor heat did nothing, nor did adjusting the mixture. I turned to 6b6, about 2 mi away. Also, I called bed and said I had an 'urgent' situation with loss of engine power, and was heading to 6b6 and gave my position. Bed tower asked whether I was declaring an emergency. I said negative, but said the situation was 'urgent.' I made a CTAF call at 6b6 and landed there normally. On the ground, I could not radio bed tower directly, but another aircraft relayed my message that I landed safely. Also, I should note that other aircraft kept quiet on the frequency. This was very good! Bed also phoned 6b6 and I talked to them.

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Original NASA ASRS Text

Title: PLT OF SMA DETECTED LOSS OF PWR IN SINGLE ENGINE ACFT. LANDED NEAREST SUITABLE. ON GND UNABLE TO DUPLICATE LOSS OF PWR. TOOK OFF COMPLETED FLT. POSTFLT INSPECTION SHOWED BROKEN VALVE ROCKER ARM ONE CYLINDER.

Narrative: SUMMARY: ENRTE LOST 200-250 RPM. LANDED AT ARPT NEARBY. MISDIAGNOSED PROB. I TOOK FROM FROM BED ON A HOT ON A HOT, HUMID, HAZY DAY IN AN SMA WITH A 6 CYLINDER ENG. I ADJUSTED THE MIXTURE ABOUT 10 MI W OF BED, USING THE NEWLY REPLACED EGT. SHORTLY THEREAFTER I NOTICED A 200-250 RPM LOSS, AND THE ENG DID NOT SOUND NORMAL. HOWEVER, SINCE I JUST HAD NEW MUFFLERS INSTALLED, I WAS NOT SURE THE ENG SOUNDED WRONG. I WAS NOT USED TO THE NEW SOUND. LOSS OF RPM WAS LIKE CARB ICE, BUT CARB HEAT DID NOTHING, NOR DID ADJUSTING THE MIXTURE. I TURNED TO 6B6, ABOUT 2 MI AWAY. ALSO, I CALLED BED AND SAID I HAD AN 'URGENT' SITUATION WITH LOSS OF ENG PWR, AND WAS HEADING TO 6B6 AND GAVE MY POS. BED TWR ASKED WHETHER I WAS DECLARING AN EMER. I SAID NEGATIVE, BUT SAID THE SITUATION WAS 'URGENT.' I MADE A CTAF CALL AT 6B6 AND LANDED THERE NORMALLY. ON THE GND, I COULD NOT RADIO BED TWR DIRECTLY, BUT ANOTHER ACFT RELAYED MY MESSAGE THAT I LANDED SAFELY. ALSO, I SHOULD NOTE THAT OTHER ACFT KEPT QUIET ON THE FREQ. THIS WAS VERY GOOD! BED ALSO PHONED 6B6 AND I TALKED TO THEM.

Data retrieved from NASA's ASRS site as of July 2007 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.