Does any one have a problem with moisture coming up from the ground and damaging the covered machine? Do you place a ground cloth down first? Does the tarp touching the hood etc. cause any damage due to the moisture?
Here in Vermont, the ground gets frozen solid several feet deep. The ground will not thaw until May. Also the air is EXTREMELY dry all winter. Moisture is not an issue.
The tarp touching the 20+ year old paint is not likely to 'damage' it any more than it already is.
The bigger concern is MICE getting up inside, nibbling things and making nests in hard-to-access areas.
EVERY year I get my snowmobile out of storage, there is mouse-damage somewhere. Last year, I had to pull the engine-shrouds off to remove mouse-nest around the cooling-fins. This year, the air-intake was totally full of pussy-smelling fuzz. Whilst I was vacuuming it out, several mice jumped out and ran off. Both of the carburetors were corroded due to the mouse-piss.
Several years ago, the mice had physically chewed thru the plastic headlight housing and filled it with a nest.
I have tried several ways to discourage mice (mothballs...etc) Nothing seems to work. The mice will build a nest right ontop of a handfull of mothballs.