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Log Data Graph by SavvyAnalysis
2/28/2020
Abrupt Drop in Oil Pressure - RV-12iS w/Rotax 912iS Sport engine
Occurred during run-up phase on 1st flight attempt.
The chart above (SavvyAnalysis) reveals an abrupt and significant drop in oil pressure at about the 6min mark. The agreed opinion of the knowledge-base at Lockwood and Leading Edge was that the problem is likely caused by trash entering the oil pressure regulator. Their explanation; unlike the the oil pump on the 912ULS which feeds the integral pressure regulator 'filtered' oil, the new design pump on the 912iS Sport feeds the integral pressure regulator 'unfiltered' oil.
Resolve: Removed oil regulator; found 3-small specks of what appeared to be manufacturing filings and no scoring on piston. Cleaned parts, reassembled, problem solved.
Aside: Based on personal experience, I strongly suggest that you verify the spark plug gaps on your factory new engine. And if you haven't already, download and become familiar with the Rotax MML and MMH manuals available free at Rotax-Owner.com.
The information presented herein is for reference only and is based on our experience.
Have a great day!
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