Hey guys I know a guy who put a 45cc rcgf engine on his aw 73" yak and its holding up great and try and get the 160os to do the vertical a 45cc will do! And I have nothing against o.s. they in my opinion are the best glow engines for starting and performance minus there four strokes then its saito but I love my 55ax's but seriously consider the 45cc, and if you did go with it I would put some reinforcing in the fuselage mostly but other than that its a really light engine and a 26cc is more suited for a 68" plane.

Later
Colin