I have a ZDZ 50 on my WM Extra. I originally had a Brisson 2.4 on it. The 2.4 flew the plane well. It would pull out of a hover, but barley. Vertical was not unlimited, although it was way up there.
The Saito 180 has a little less power than the Brisson 2.4 . I was swinging a Bolly 18 X 8 at 7200 rpm's .
WM says not to use more than a 160 2 stroke. Most people that have tried this set up have been disappointed. The average weight people are getting is about 15lbs. Mine is 15 1/2 lbs.