For those of you who may get or while waiting for the YS 110 or an OS 91 theres another option for 90-110 size pattern planes . It's the new OS 120 AX (still side exhaust[

]). If you need additional info just go to
www.singahobby.com. Below are the specs.
Displacement: 19.96 cc
Bore: 30.4 mm
Stroke: 27.5 mm
RPM: 1800 ~ 9500 r.p.m
Output: 3.1 ps / 9000 r.p.m
Weight: 647 g (without silencer)