Bass1,that's a sweet looking bike. I was going to make one and checked with local police and they said no more than 49cc and if riding at night it had to have a headlight,tail light and reflectors on it. They didn't mention any speed.There's two that I've seen locally.One that a lady has I think,a 35cc Honda engine with friction drive and the other is on a mountain bike and has a Stihl 40 some cc chainsaw engine on it and uses the original pull starter and is chain driven.
There's even a forum for these.
http://www.motoredbikes.com/forum.php