Are we talking over winter storage here, or year + storage? I think you should leave oil in it, but only the amount specified. By using the Seafoam, (or trans fluid, or motor oil, whatever) that leaves an oil coating on the whole intake tract, and combustion chamber, and thats also why you should store it with fresh oil in it. Just before storage warm it up good to get rid of all the pollutants in the engine, then drain the oil and refill with fresh oil. Don't give the engine a chance to get cold again. Start it up with the fresh oil in it, and stall the engine out with the seafoam. If you can keep it out of the weather changes, and humidity that is so common east of the Mississippi, this should minimize the condesation that will build up. Ever see your concrete floor sweat on a warm spring day? That happens because its exposed to humid warm air. Keep you garage door closed, and it minimizes that condensation. This should get through a year or so of storage.
