Today I started the engine for the first time with the help from my friend and fellow aviator Karl Lindenthal. We noted a knocking sound in the engine which was more audible at low rpm. We susspected a lazy hydraulic lifter. The Jabiru factory have confirmed our theory and are footing the bill for a LAME to travel to my place to carry out the repair. The level of customer service from Jabiru is second to none. Well done Jabiru.