im don I live in westland MI usa I have three 80cc 700c bikes they go between 40-45 and only have 10 miles on them at the most. I started in this motorized bike area with my 63 solex that was a blast!!!! now ive been into these for 4 yrs now my first motorized bike was a 49cc but it wasn't fast enough to keep up with traffic and I got pulled over a few times then I decided that's enough so I bought 3 returned to manufacture motors for 30 apiece and started rebuilding. I have found that if you get a mount for the Schwinn occ chopper that you can mount the motor to a table get a pull start and turn the exhaust upside down and you can test the motors without mounting it to the bike and finding out theres something wrong. im trying to get one of these going at least 50MPH I know im crazy well I have a site on facebook its www.facebook.con/motorizedbikes
check it out and post your pics there.