I have an MDS .48 engine in my Ultra Stick and its been running really badly. Several people have tried working on it but no good[&o]. It runs good level but when I hold it up it either looses RPMs or just plain quits and when flying inverted it looses RPMs. So, I've been planning on getting a new engine for it and since I live at high altitude (and want to take some lead off the noze) I was thinking about a .60 size engine. First question- how much does an MDS .48 with a Tower Hobbies muffler probably weigh (the reason is because I want something at least 3 oz. heavier)? Question #2- Would an O.S. 65LA [link=http://www3.towerhobbies.com/cgi-bin/wti001p?&I=LXPUE1&P=SM]link[/link] be very good for it? Question #3- what size prop would be best for it?