Hi Mike, welcome. Here is a link to laws section,Laws and Legislation - Motorized Bicycle Tavern at Motorized Bicycle Forum
The 2 strokes are kind of weed whacker sounding. 4 strokes are almost as loud but have more a hum like a lawn mower. The odd thing about these lil wonders is they are very addicting and great fun to ride. Most folks seem to be planning their next build during their first build. All the advertisers to the left are members here. There is also a review of dealers thread.
Glad to meet ya!