I have never owned a DZ but I still have several of the old 1.20 and a couple of the 110s. To date I have never had a problem with one, well no problem caused by the manufacture.
I do have one of the 140 DZs I was given for a parts engine though but none of the parts do me any good except for some of the screws. {maybe?} I do need a new cylinder for a 110, my bad, broke it in a crash on the first flight after a rebuild, Broke right at the header.
Anyway, anyone need any 140 parts I have a few.