If there's no fiber washer between the mag post and the aluminum hogshead on my '14, will that cause starting/running issues with the mag?
May leak oil at this point, Nothing to do with running,
Bill, use an old file folder cut to fit to make a replacement until you can get a proper gasket.
And remember, "there is nothing more permanent than a temporary fix that works!"
Why waste a good, but old, file folder? Cut a temporary gasket from a cereal box.
First of all, they didn't use a fiber washer. Second, they used felt in 1914. Third, the correct gaskets are available from the vendors, or make one yourself as mentioned above.