Thanks. I had an OS 1.60 on an ultimate and HATED it. I could never get a full flight without a deadstick. I tried every trick in the book with no result. I want to go gas with this one. I suspected the 26cc would be a little small. This plane was given to me, so I 'm not going to spend a fortune on an engine. I may go with a 45cc engine, but will need to change the main gear so the prop will clear. This will be a Sunday recreation plane, that is why I want a cheap engine. This one might do. [link]http://www.hobbycity.com/hobbycity/store/uh_viewItem.asp?idProduct=5460&Product_Name=45cc_G as_engine_w/_CD-Ignition_3kw_+[/link]