Everything has one answer - it depends. It depends on the storage
conditions; humidity, swings of temperature, vibrations, etc. It depends on the types of seals
and gaskets used in manufacturing; drying out; shrinking; evaporating. It depends on whether it was test run; exhaust
gases and molecules, remaining fuel
liquid in system. It depends on whether there was break-in oil
or completely dry.
Depending on how it was stored, I would fill it up with oil
, turn it over a few times (without firing) and let it sit for a few days to allow those to get to the seals
and gaskets. Then run it.