“Excess” oil appears during flight

I experienced an increased oil level several years ago.  According to the Rotax Troubleshooting guide the problem could be diesel fuel contamination.

Since I had a fair number of hours on the oil I changed the oil.  I didn't ask the analysis lab to test for diesel because it would have been an additional $25 and even a positive result would not have changed anything.

I had purchased about 50 gallons of ethanol free 91 octane fuel from a station located near a marina, that advertised to boaters.

I stopped using fuel from this station.

No problems since 

James Porter

Just one piece of advice.

when checking oil level after burping proc. wait 5 seconds after stick insertion. Then extract the stick and check oil level. Oil stick guide is narrow and sometimes (oil very cold) it can takes some time to equalize oil level between stick guide and surrounding oil tank after the "piston" effect of stick insertion.

little advice. great effects on oil checking consistency and repeatability.

"Problem #1, I don't always get consistent oil readings, even when I burp the engine. There have been times when I add oil to fill up the tank (after being burped) but when I check the fuel a few days later the oil level is higher and I have to remove some to keep from overfilling. Based on my experience, I sometimes see different levels of oil after I burp the engine. One possibility is that you are inadvertently overfilling the oil due to the inconsistent burping?"

Are you using the current version of the Rotax oil fitler?