if you run your engine dry at the end of the day it helps to prevent rust, drain your tank and then run it out of fuel, if you are planning to fly the next weekend and you are concerned about rust then a little W-D40 in the carb for 2st engines, works to prevent moisture getting to the berings,there are a bunch of ways to store your engine for longer,ATF fluid works well,along with 3in1 oil, as well as pure castor oil when I am not running a engine much I use 3in1 in the carb and in the plug hole just a few drops then spin the engine without the plug in it a couple of times ,replace the plug and store it in a zip lock bag I am sure there are other ways that will soon get posted.