Oooooommmmmmmmm.................
Respond when you are able. Good thing you aren't in junior high and not responding to your girlfriend's texts!!
OK: it could be the float valve. I would do what was advised in post # 11 and reproduce your takeoff AOA and power at altitude and see if the problem occurs. It seems odd that a sticking float valve would be that momentary and not during cruise. No RPM loss, right? How many hours are on your engine? Sometimes these problems are tough to chase down.
Case in point: I was having rare momentary pauses in the Cub that were almost an afterthought. Kind of like "auto-rough". Did I feel something.....? Hmmm. I wasn't sure I was
really even feeling anything. Then one fine morning after flying to a back-country strip an hour away, was halfway back home (one hour out and 30-40 minutes of flight time coming back) and had a sudden but significant power loss for about 5-10 seconds......or was it 2 days....it seemed like forever! I did all my engine out procedures (which I regularly practice, by the way, including 'where are we going to land'....) and was setting up to put her down in a stubble field and the power came back. Landed at a friend's strip 5 minutes away and did a ground runup: nothing. Flew the 30 minutes home without incident and nothing felt. Do I have engine instruments? Yes: tach, oil pressure and temperature!
My altimeter has one needle!
She was born in 1946!
o hold only 80 knots
Drained the float bowl (PITA), took the carb screen out, the gascolator apart: nothing. Finger screens in the tanks and quick drains out and cleaned: nothing. Mag check including wires: nothing. Compression check: nothing amiss. Spark plugs: all checked out. Huh. Flew for 3-4 more hours before she did it again. Time to get serious. Changed all soft fuel lines and blew out all the hard lines. Inspected tank interiors. Installed a new, more modern gascolator. Installed rebuilt mags (~400 hours since new on the old ones) and carburetor. Took the selector valve apart and cleaned it. New spark plugs. What else was I missing? She has an "Armstrong" starter (hand propped) and, after all that, when I was starting her, felt a
slightly soft cylinder.....with the compression test being
normal. She started normally so I warmed her up (normal running) and took her to the runup area. She ran up fine but didn't
feel quite right at full throttle. Sometimes that
feeling is all it takes. Took her back to the hangar and shut her down. Pulling the prop through and, after
ALL THAT, found a stuck exhaust valve on one cylinder!! Short end of a long story: replaced the cylinder and she has been fine since. And look at all the new things she has!
So: could you have a momentarily sticking valve? Done the wobble test lately? If you are sending the carb off you'll have plenty of time to do that! Just an idea. IMHO; YMMV....