Great idea. I've owned N750ME C model, s/n 717 since Nov 05 and have flown 400+ hours in her.
I've had 2 electrical failures off the same alternator: the first time in flight when a grounding lead separated and the second on the ground. The field was producing too much current and blew the voltage regulator. Zeftronics will rebuild voltage regulators.
I was in cruise on BOTH TIPS when I reached down to switch to a main with the tips almost empty and found the selector jammed. A roll pin had sheared and jammed the selector torque tube. Declared an emergency (second in my career) and landed at the nearest airfield. The fuel valve has since been rebuilt at annual last year and the torque tube and roll pins have been carefully fitted by my shop. We had a similar incident during military primary in the SF.260MS when a student and instructor were in the pattern and switched mains but the valve didn't switch to the other tank for the same reason. The engine quit and they landed short of the threshold, no injuries but the plane suffered strike damage / Cat 5 (depending on your military affiliations.)
The boost pump was replaced last annual and was found corroded to the point that fuel was found in the armature asssembly. Could have done a reenactment of TWA 800, and every eyewitness will swear that it was a SAM. It lasted 489 hours.
The vacuum pump inevitably failed, but Murphy was asleep on the job--happened in broad daylight with unlimited vis. I'm going electric with a Mid Continent 4300 Attitude Indicator. The local FAA will allow a vacuum system hysterectomy if you have the battery back up. The Aspen PFD is not certified for the aircraft yet. The Garmin 500 / 600 is, but very pricey in terms of cost and the panel work necessary. While we're on instruments (pun intended) if you have the Collins PN101 HSI system, overhauled units are available for less than $6000 (entire system) and you can get overhauled units of the various components on exchange quite easily.
Autopilot, S-Tec 50
The autopilot was spontaneously disengaging (no fancy aural warnings unlike my Falcon 2000 at work.) This time Murphy was on the job--coming home to Atlanta after visiting Frank Strickler in Tejas, the auto pilot chose the ONLY cloud in about 5 hours flying to stop working. My first unusual attitude recovery in anger. After extensive troubleshooting over nearly a year, it was found that the roll servo clutch was disengaging at random. No rebuild offered; replaced with new unit.
One of the celebrated bellcrank bolts had been found cracked and replaced by a previous owner, Bill Vitale. Last annual I had both bolts magnafluxed and the original was still good after about 1400 hours. The replacement bolt was found cracked after about 800 hours. This was an intermediate part number. Replaced with the latest part number item. The system gets thoroughly greased every annual. This means removing the seats and floor for access.
Oil pressure gauge
The oil pressure gauge (if you have the instrument cluster with small gauges) will work perfectly for about 60 hours after coming back from the instrument shop before the needle begins to vibrate in normal operation. Probably caused by sludge. Sigma Tek will rebuild them, but you have to go through a shop; they won't deal with individual owners. Takes a few months. They were supposed to have been doing a large batch for Libya when I had mine in early this year. If you don't want to be AOG that long, buy 2 gauges.
I'm based at C29, Middleton Morey Field near Madison, WI and the shop, the Morey Airplane Company, do an excellent job on annuals and other repairs. I let them have the Maintenance, Parts and Repair manuals to put on their hard drive (thanks to Dr. Steve Leonard for the disk.) Something to think about if you're at Oshkosh and have a problem. I have used Epps at PDK and Wisconsin Aviation at MSN for avionics and they do fine work.
Mike, thanks for the quick, responsive and reliable logistics support! I realize the parts are priced for small governments, but that's better than owning some exotic warbird type when you can't even get ANY parts. I wonder about owners of P3s and FW149s. Even Yak 52 owners have problems getting M14 engine parts.
Hope that helps. Drop me a line if you have questions.