Anticept Posted May 15 Report Share Posted May 15 The temperatures outside won't directly matter much, and I operate out of a towered airport where sometimes you have to sit there and wait for the takeoff clearance for a good bit. I've had to shut down due to engine temps approaching redline on particularly busy days. What I HAVE seen strongly correlate to the issue is how hot the gauges read before hitting full power and taking off. Long runups and waits gets things COOKING under that cowl and the fuel issues are especially prone to happening then. Quote Link to comment Share on other sites More sharing options...
FlyingMonkey Posted May 15 Report Share Posted May 15 3 hours ago, Roger Lee said: The only time we see any type of vapor accumulation (not lock) is when we park to go eat somewhere and the heat in the cowl just sitting there heat soaks everything. I think that's at least part of what happened to me in Florida. We flew to St. Peterburg and left for several hours to eat and visit a museum. It was a hot day and the airplane just sat on the ramp soaking in all that heat plus the residual heat from the previous flight. Upon departure we had two quick power loss events, then it cleared up. Quote Link to comment Share on other sites More sharing options...
FlyingMonkey Posted May 21 Report Share Posted May 21 I flew over an hour yesterday with a 50/50 mogas/avgas mix with no issues. I think I'm going to keep adding mogas to dilute the 100LL and see how that goes. Quote Link to comment Share on other sites More sharing options...
Anticept Posted May 22 Report Share Posted May 22 I'm having a fit with fuel pump install. The free flow check valve uses AN6 flare, the fuel pump is 1/8th npt, the flow transducer uses 1/4 npt, and the aircraft uses 7.5mm ID hose. GOT TO LOVE IT. Quote Link to comment Share on other sites More sharing options...
Anticept Posted May 22 Report Share Posted May 22 Okay I just opened fittings on the fuel distributor that is after the fuel pump to take some measurements for some test fittings, and that was after a run over to another shop to get a transponder test done. I was having wonky readings. As soon as I opened the fittings, I became flabbergasted at the amount of air I watched bubble and sputter out for a bit before fuel started flowing clean. Quote Link to comment Share on other sites More sharing options...
Madhatter Posted May 22 Report Share Posted May 22 Just a thought, don't go nuts over this. When I reworked my fuel tank suction tube end plates I noticed that it was very easy to get the suction screen well above the tank floor, especially on the left wing. This could cause air being introduced into the line especially when the tank is not full. In a case like yours all options are on the table no matter how remote they might be. This is how it's done with all engine and aircraft manufacturers, sometimes it's what everyone says can't happen. Ask the guys who found the hard over rudder issue on the 737 years ago, something no one expected. Quote Link to comment Share on other sites More sharing options...
Tom Baker Posted May 22 Report Share Posted May 22 11 minutes ago, Madhatter said: Just a thought, don't go nuts over this. When I reworked my fuel tank suction tube end plates I noticed that it was very easy to get the suction screen well above the tank floor, especially on the left wing. This could cause air being introduced into the line especially when the tank is not full. In a case like yours all options are on the table no matter how remote they might be. This is how it's done with all engine and aircraft manufacturers, sometimes it's what everyone says can't happen. Ask the guys who found the hard over rudder issue on the 737 years ago, something no one expected. The fuel pick up for the CTLS is different than the SW. It is in the very rear bottom corner of the tank, and can't possibly be re-positioned wrong. Quote Link to comment Share on other sites More sharing options...
Madhatter Posted May 22 Report Share Posted May 22 11 minutes ago, Tom Baker said: The fuel pick up for the CTLS is different than the SW. It is in the very rear bottom corner of the tank, and can't possibly be re-positioned wrong. I stand corrected Quote Link to comment Share on other sites More sharing options...
Anticept Posted May 24 Report Share Posted May 24 Something to add here. I noticed my fuel pressure sensor was probably original, so I went ahead and replaced it. Apparently the old one was reading lower than what was really going on, as the new one reads over half a PSI higher, sometimes more. That doesn't change the fact that we have had stumbles with the engine, and this is the ONLY thing I have changed so far. I was checking for clogged orifices and they're all clean. Still moving forward with a fuel pump. Finding the right fittings is a CHORE. Quote Link to comment Share on other sites More sharing options...
FlyingMonkey Posted May 28 Report Share Posted May 28 Down to about 20% 100LL over the weekend, and it was almost 90°F. No issues even in a hard climb. I'm happy with this ratio, I just put in 2g per side of 100LL about every 20g of mogas. Quote Link to comment Share on other sites More sharing options...
Anticept Posted May 29 Report Share Posted May 29 We had a near miss issue here on the field. A piper cherokee, 1964 model lost power on takeoff. They had plenty of runway left and set it back down. During taxi back, they had erratic pressure readings even with the electric pump on. On this model, the fuel pump is located in the engine bay along with the hose attachment leading to the mechanical fuel pump. They run parallel to the inlet of the carb. When he got back to parking, I got called over and couldnt find anything obvious, then thought for a moment and asked about mogas. He confirmed he uses it and has a mogas STC. Asked if he used ethanol free which he claims he does (hopefully he's not fibbing). Told him try a tank of avgas to see what happens. No issues. Ohio mogas SUCKS. Quote Link to comment Share on other sites More sharing options...
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