I have one just like it. It's a Manco Thunderbird. Mine was around a '93, and they were still making them 'til just a year or two ago. The later models were called the Bandit. They are still in business. They merged with another company to form American Sportworks. They make go karts, scooters, UTVs, etc. Believe it or not, many of the parts for the old mini bikes are still available. I bought a chain guard, gas tank, kill switch, and some other odds and ends.
I've got mine on Craigslist for $250. It's got a 5.5hp clone on it. It'll shoot out from under you if you're not careful.