Oil Purging
I had to replace the oil pressure sender and because of the thread difference between the old sender and the new one I had to replace the oil pump housing. after installation I completed the oil purge procedure. It took three rounds of purging but I finally got all the the lifters full. I have flown 20 hours since the installation. Two days ago while burping the engine I heard a clicking from the left rear cylinder head. Removed the cover and checked and sure enough the intake valve lifter showed some movement and evidence that air had creeped back into the lifter. I completed three more rounds of purging to no avail. Any suggestions would be appreciated. We have no local Rotax mechanics so if I cant get this fixed I will have to load the plane up on my trailer and haul to a Rotax facility 40 miles away from my airport.