First off, remove the oil. All the internals will still have a film on them anyway and you lessen the risk of the old oil holding any moisture. Remove the spark plug and carby and block the inlet, exhaust and plug hole. Race tape is good. Also block any breather outlets. We don't want any air or moisture getting in. I store engines in plastic crates with lids to prevent dust etc. Cheap as chips at the bargain shops.