At 65 hours on my Rotax 912S, the oil pressure display on both the D100 and the D120 commenced fluctuating equally between the high 40s and the low 50s.
Can someone tell me the mostly likely place to find the cause?
Then it's either a broken/iffy wire, a bad sender, or your actual oil pressure system in the engine is bad and we're just showing you the real pressure variations.