Leak at the cylinder base

… or if you get sent pictures …

It's dark early in December and the weather isn't great.
So you can use the time to take a closer look at the plane and give it a good clean.

Stop - what is that?
Oil where it doesn't belong.¹⁾

… there actually are, but I don't feel like writing my fingers to the bone.

so here the solution in at least 80% of cases:

The inconspicuous part 38 is missing here.
P/N 431570 O-RING 10.82 X 1.78

After the cylinder has been removed, it looks like this:

Order and install the O-rings.

Of course, one wonders why there are no O-rings installed.
Quite simply: after a modification to the crankcase, no O-rings were installed here.

Read in the SI-912 i-006 R1 / SI-912-019 R3 / SI-914-021 R3
**This is also the repair manual for it\