Originally Posted by
jiott
If you are the builder of an E/AB aircraft you are eligible to apply for the Repairman's Certificate for THAT aircraft, which then allows you to do all repair and service procedures and sign them off. The simple answer is: I don't know of anyone who has ever gotten in trouble for doing an oil purge. The Rotax manuals say many things which sound mandatory, but in most cases are only factory recommendations for us E/AB people. Rotax does build certified engines and the rules are different for those.