Due to deviation in the manufacturing process, some cylinder heads may have an oil leak in the intake channel. There is a possibility of small machined through holes, which can increase the oil consumption which may result in engine...
I just came across a bulletin from 2003 that may be worth keeping in mind when you registration inspect your trike, and especially if your wing is older than 2004.
http://www.airborne.com.au/pages/directive_pdf.php