"Scotland, Births and Baptisms, 1564-1950," index, FamilySearch (https://familysearch.org/pal:/MM9.1.1/XB96-LYV : accessed 12 April 2012), Isaack Young (1690).
https://familysearch.org/pal:/MM9.1.1/XB96-LYV
Of course this does not confirm he is your Isaac Young. Has parents listed.
https://familysearch.org/pal:/MM9.2.1/SR4T-WVL
"Pedigree Resource File," database, FamilySearch (http://familysearch.org/pal:/MM9.2.1/SR4T-WVL : accessed 11 April 2012), entry for Isaac "The Immigrant" /Young/.