The little 2.0 was/is one of the best A&M engines...Only thing I could fix would be a bent crank or carb parts..the piston and cylinder are Sachs parts, probably still available from a chainsaw dealer, Sachs was bought by Makita a few years ago...
It is as good as anything today in the same size range....Brison and Fox made the other A&M engines, maybe they also made the 2.0...If not, they should have