Tito22

Hey all, thanks for the replies. I looked at the ignition and power theories after the suggestions here. I realized I could download the engine data and that helped out a bit. #2 cylinder is definitely off... I can't tell if it's just the "weakest" cylinder and loses power due to getting bogged down by a higher pitch RPM or if the cylinder is lagging at higher power settings and that's preventing full power. Previous flight had much closer EGT and CHT spreads, this attempted flight had #2 about 25 degrees cooler and CHT about 50 degrees higher than other cylinders. Before pulling the prop, I pulled #2 plugs and the bottom one was a little dirty and had a close gap. We re-gapped and tested, good spark all around. I'll try running it before I pull anything else. Guess I shouldn't have been quick to assume it was the governor again after all the problems it gave us... Thanks again and I'll post back with results... 21 Aug.pdf

Thanks so much guys for the responses. I’m going out to hangar now, gonna try and measure my prop blade angle to see if that somehow got out of whack. Also going to borescope the exhaust and intake. I am worried I’m going down the wrong rabbit hole with the propeller idea. @Z W the only time I tried to go full power was during the initial takeoff that only got me up to 2200-2300 rpm and a sound of engine not working well. The fuel system is a thought. I was concerned about going too high power with low rpm so I only got to about half-2/3 throttle before I wimped out. Fuel flow seemed about as I expect for not WOT. I’m at 1200’ and it’s hot but not a really high DA day, about the same as I did on other days with test runs and were in OK so not much elevation difference from the other airports. I think what really threw me into not thinking it was an engine thing is the fact that this happened between sorties, it wasn’t like a rapid change in flight in engine operation which I would have assumed would have happened…

Subtitle: The overhaul from hell... Just got my M20J back from overhaul. Mind you this was after two test flights. The first flight, oil leaking from governor, we pulled it and overhauled it. Put it back on, second test flight was leaking from gasket. Replaced that gasket, third time was the charm and no leaks and I brought the Mooney back home. Next weekend, I flew it about 8 hours, to and from Omaha and Oklahoma - performed great with no issues on the flight. After landing, taxi back, and shutdown was uneventful. Skip forward a week and I go fly again. Engine start, taxi, runup was uneventful. Mag check was good. On takeoff roll engine sounded weird and like it wasn't making full power. I look down and see ~2200-2300 RPM. I abort the takeoff. A Couple of more static runs and it seems to be governed just above 2000 RPM. I pull the cowl, check the cable and it seems to be making it to the low RPM stop just fine. I was sure it was the governor since it was having issues. I have the governor removed and sent to the place that did the overhaul. They said it bench tested good... Has anyone seen anything like this before? Looks like I'm pulling the prop to send it to the shop to see if there's something wrong with the prop. It seems that with enough RPM there is something leaking into the prop hub to increase the oil pressure to increase the pitch on the blades. Attached videos show the runup. When I took this video, it looks like #2 cylinder dropped off (not sure if that was due to over boosting it or something else) but fuel flow and manifold pressure all looked good. #2 seems to keep good ignition the rest of the runs. I didn't want to run it too much over square. I also haven't checked the accuracy of the tachometer but it seems to be sounding like the prop is digging in and causing rough running.