How can I fine-tune idle mixture?

How about a discussion of the scalloped wheel on the injector pump for an IO540-C4B5 engine? My engine will “”load up”” at idle and I have to run the rpm up to about 1,200 quite often during taxi. Also the engine will “”talk to you”” on final with the throttle closed. I have tried the idle cut-off procedure looking for rpm rise, but this doesn’t seem to help.

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What is normal oil consumption?

I have a 2005 Robinson R-44 Clipper II that I purchased new. The engine is a 540 injected Lycoming. I broke the engine in on mineral oil as suggested and changed to ashless oil after the initial 50 hours of break in. The ship has used about 1 quart of oil per every four hours flown on average from day one and continues today (there are currently 240 hours on the ship). During the 200-hour inspection, we checked compression and found all cylinders to have excellent compression. I have always noticed oil coming out of the breather after shutdown and have also noticed oil on the rear cross tube, which would indicate the loss of oil during flight. I have never seen blue or any unusual smoke out of the exhaust. The plugs looked perfect on the 100-hour and 200-hour inspection with no dark spots or indication of burned oil. The ship has plenty of power and always starts and runs great.

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Confused about replacement parts?

Q, I have a Lycoming O-320 150 hp engine with no suffix in my PA-22 Tri-Pacer. In one of your articles you list the O-320-A1A and the O-320-A3A as the numbers to refer to for replacement parts. Lycoming does not list an O-320-A1A and shows the O-320-A3A fitting a Piper PA-23. Lycoming lists the O-320-E3D as the engine for my PA-22. I’m thinking of either replacing my engine or overhauling it, but I’m not quite sure what to look for in either case.

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The XR-7755: The whole story

I was reading about the XR-7755 on the Internet and was wondering if you would clear something up for me. Most sources say there were two engines made, but I’ve found there were three versions. The first was set up for a single output shaft, a second had contra-rotating shafts and the third was set up with fuel injection. Are some of these versions the same engine or were there three engines?

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