Rotax 503 powered Quickie
Quickie originally designed to an 18HP Onan generator engine,
the Rotax 503 weight is comperable but puts out 50HP. The builder, at
Camarillo, CA, said he limited his Vne to 135mph cuz he hadn't
yet balanced the control surfaces. The plane easily wanted
to go much faster. And that was with a relatively flat pitch prop too.