I started my 25hr inspection on my 912is with an oil change. I did not have a differential pressure tester available at the time. After a short warm up I removed the bottom plug from the oil reservoir and emptied it. The oil was dark but appeared normal and there was nothing visible in it. I saved it in case I want to get it tested.

I removed the magnetic oil plug for inspection. There were some deposits (see image), more than none, but not a lot. All appeared small in size and nothing was sharp after rubbing between fingers. However, I’m not sure if this looks like more than I should expect for the first 25 hours.

Lastly, I removed the oil filter. This thing was way too tight. I believe this was from the factory though. I replaced it and tightened it as per manual. I then opened up the old filter. As many times as I’ve changed my car filter I’ve never once opened it. It was interesting. After cutting out the paper filter and letting the oil drip off (left it about an hour) - there were no large deposits of any kind. Running a magnet over it didn’t pick up anything. However, using a flashlight I did see about 10-20 sparkle/glitter sized flakes on the shop towel and embedded in the paper. Is this expected or of a concern? (see images)

After replacing 3 L of oil as per manual I rotated the prop 20+ (about 40) times as I was expecting a burp - but I never got one. Is that expected? Oil level on the dip still remained just about at the minimum.

I removed all the spark plugs. I believe they look ok. Consulting google I don’t see anything of major concern. Would you think differently? (See Images) I replaced all plugs with a NKGs gapped to 0.032-0.033 in.

The differential leak test on the 912is took place after my oil change due to not having it available. Starting with cylinder 3 I found TDC using a rubber glove on the end of the connected hose. I slowly increased the pressure to 80psi and it was holding at 78psi. However, I noticed I was getting a gurgling/burping sound in the oil. This seemed very strange. I repeated on the remaining cylinders and noticed the oil gurgling starting anywhere from 10-40psi, although there was no pressure change detected on the differential. My oil reservoir was now nearly flowing over. What’s going on here? Is this expected? I wouldn’t think so. (see video)

During the 25hr (ecu indicated, 28hr timed from engine start) I only used about ¾ litre of oil. There were no other concerns during flight that would cause suspicion. (ie loss of power, sounding different etc).

During visual inspection everything else was ok except for a very small coolant drip (already known) at the connection to the radiator. Additionally it was found that this same hose was rubbing/touching the cylinder fins and had started to melt away the protective sheath in that area. This was fixed by shortening the hose to allow a better (straight fit) onto the radiator connection. This provided a gap at the fins as well as improved the fit which should remedy the small drip. Additionally it was required to shorten the heater core attachment on the T junction of this hose to prevent additional pressure pushing the hose back towards the fins. (See images).

All other inspection points had no issues.




https://res.cloudinary.com/tracstarr...ressureOil.mp4
https://res.cloudinary.com/tracstarr...SparkPlugs.mp4


Oil Magnetic Plug
https://res.cloudinary.com/tracstarr...121_134047.mp4

https://res.cloudinary.com/tracstarr...121_134038.jpg

https://res.cloudinary.com/tracstarr...121_134042.jpg

https://res.cloudinary.com/tracstarr...121_134204.jpg

https://res.cloudinary.com/tracstarr...121_134045.jpg

https://res.cloudinary.com/tracstarr...121_134036.jpg



This is after oil change and rotation of prop by hand
https://res.cloudinary.com/tracstarr...128_105129.jpg

https://res.cloudinary.com/tracstarr...128_105131.jpg



Oil filter tear down
https://res.cloudinary.com/tracstarr...128_094408.jpg

https://res.cloudinary.com/tracstarr...128_094329.jpg

https://res.cloudinary.com/tracstarr...128_094521.jpg

https://res.cloudinary.com/tracstarr...128_094420.jpg

https://res.cloudinary.com/tracstarr...128_094445.jpg

https://res.cloudinary.com/tracstarr...128_094341.jpg





--Keith