Wayne.... In my previous message I described my problem and cautioned that it might not be the same as yours. After looking again at my response and noting that Harry also mentioned it as a possible cause, it occured to me that I might elaborate for the benefit of others who might someday experience my problem, particularly while in flight.
I lost engine power in flight but found that if I closed the throttle, then slowly nursed it forward I could get approximately 1700RPM maximum. If I opened it to cruise or full throttle settings the engine quit (I made it 3 mi back to the field by slow-flying).The effect was like pulling the mixture control to full lean, but worse. (Wayne, you didn't mention anything about throttle movement) The passageway in question is actually two passageways. One is from the mixture/disk chamber to the throttle body, the other from that chamber to the float chamber. It was the former that stopped up on me. Harry described this. The best article I've ever seen on this subject was in the October 1997 issue of Coupe Capers by Scott Reaser, who has written many fine articles in the past. Many are worth repeating. His article is complete with sketches and covers this subject thoroughly. He indicated the carb could be cleaned on the plane but I believe I removed it to do so. After I had cleaned the carb my full throttle level flight RPM increased 25+RPM. Apparently the passageway had been partially blocked for some time. Incidently, a similar experience can occur with the Marvelous/Schlebler carb(the man who brought us Marvel Mystery Oil), but for a different reason. If, in overhaul, the tang on the float is bent wrong so that the float does not drop low enough(i.e. not spec) this slows bowl refill. The effect is delayed. You can get a good runup and even get airborne before you lose power. With luck you can even get enough part throttle RPM to let you land. Best Regards....Cliff
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