Bored the cylinder to 60cc (44 mm) and turned about .009" off the base of the cylinder. Using two head gaskets. Did a little port work. Drilled the main jet with #66 bit. Runs strong. Much better off the line. Tops out near 40 mph. Adapted a handlebar gooseneck from a Red Line BMX bike to change handlebars, then moved the headlight down and forward -- added beefier tires, too. One of my shop mates donated a Suzuki DS80 pipe that he and a buddy cut up and welded a few years back -- unfortunately, they'd had a few beers when they did it; the header pipe was a mountain of slag and pin holes. Took a couple of hours of grinding to find the original metal, then I cut and spliced in a one-inch extension to clear the stator cover. Shortened the stinger a bit, too, and reduced the outlet ID to about 12mm. With the larger cylinder, the pipe now hits at about 18 mph and takes it up to about 38 mph. Way more bottom end power, too. Added some Stingray chrome fenders and replaced the head and base gaskets. Super reliable, now -- starts first try every time. It has become my preferred ride for shop errands and snack runs. Sold it on 6/20.