If you have bands on at the base of your cylinders it sounds like you have a Reiff preheater. As I understand it do to a change in the cylinders on the "newer" Jabiru 3300 engin ...
When I first built my Lightening I flew the plane for maybe 60 hours before putting on the wheel pants. During that initial 60 hours I never had any shimmy. Almost the first time I taxied t ...