They are great little motos. When tuned properly can get pretty good milage. My 61 Tempest with the 4 cyl gets 18 in town & have gotten as high as 28 on the interstate. Some parts are getting pretty hard to come by. Most engine parts are readily available. Probably the best forum for the 61-63's is here http://forums.performanceyears.com/f...play.php?f=427