The humidity here turns nitro into rust soup if left for too long. If mine is going to sit for a while I pull the back plate and put after run oil directly on the rear bearing and also on top of the piston through the glow plug hole. Put the back plate back on, make sure fuel line is pinched, pressure line disconnected, hold a paper towel over the glow plug hole and turn it over a second or two with my starter to make sure the ring gets coated. It's stayed in pretty good shape for a long while now. When I'm flying every day/every other day I don't worry about it.