Larry,
this is what I know from rusky sources and friends over there: it does run on a radial piston, mounted in rear.
Heli came out for debut in '88 and boasted reliability, low DOC, and esp it's "fully aerobatic" capabilities. Not until 96 was is put into substantial production (well, goals of 50 to be put into service, mostly police work).
"Joint stock company "Mi light helicopters" specialises in development and production of the Mi-34S helicopter and its modifications, as well as sales, maintenance and technical support for Mil aircraft in service, pilot and ground crew training. Production of the MI-34S is set at Arseniev-based Progress factory with a yearly manufacturing capacity of 350 airframes.""
seems like a fun ship! nice looking too.