I wrapped my magneto to keep rain off of it but now its looking like my working on the tractor will be done for the season.   I am trying to decide if I should just remove the magneto over the winter and store it inside or if keeping it wrapped would work OK. Northern IL so we get plenty of cold and snow. Any suggestions?

Thanks. That's a good idea. I would like to leave it on because its not so easy to get back on and if the impulse drive gets moved then I have to retime everything.

I wouldn't bag it. Any moisture that might be in there will stay in the gag. I would make some type of cover that would let air flow but keep any water or snow off of the mag. Just my 2 cents.
ChuckC

I was thinking about the moisture also. I will cut an opening in the bottom of the bag to allow air to circulate but not come in from the top

A lot of farmers here used to cover a distributor with a rubber glove, a hole in each finger for the wires and where you'd stick your hand in left open and loose around the base of the distributor. The fingers were punched with a small hole to stick tight to the wire. It pretty much eliminated moisture problems from water, yet the cap and wires could dry out. Something similar should work on a magneto if it was big enough to cover. We also found that synthetic rubber inner tube carries electricity, so not quite so good.

we cover most of or stationary engines with old tractor inner tubes split em on the inner radius and cut into segments yes you get carbon black over yourself as they weather. but it keeps the water off.
another method is grease lighly smear the seams with grease to moisture proof it some what.