I would consider doing a soft pickle (my term :P ). I would research what ROTAX recommends for long-term storage. Some things I might consider:
-- Change oil before long-term storage. There are special "pickling" oils on the market, but they are generally used for storage involving many months/ years and may not be suitable for our ROTAX 912 engines.
-- Drain all fuel from aircraft and engine.
-- Disconnect battery.
-- Remove spark plugs and spray some oil in cylinders and install desiccant plugs.
-- Install desiccant plugs in exhaust outlets. Note that some owners have installed desiccant air pumps to dry the air inside their stored engines.
-- Cover carb intakes.
-- Do NOT turn the engine or prop once it is pickled.
Others may chime in as to how sensitive 912s are to internal rust/corrosion. It is my understanding that the 912's nickel-plated cylinder walls tend to resist rust/corrosion better than plain steel cylinder walls.
Anyways, those are my thoughts.
ps - Most aircraft engine manufacturers I am aware of do not recommend running engines on the ground for long periods of time in an effort to heat up the oil. Apparently, this could lead to hot spots within the engine that don't adequately cool.
