Welcome to the site, Mailbuster!
Hmm, it sounds like maybe something with the throttle/governor linkage is not connected or adjusted right. Perhaps maybe even something broke or missing?
I pulled up a diagram of the linkage seen here. For starters, I would confirm that everything is connected up properly and nothing is missing.
Here is more info regarding governor adjustment. http://www.briggsandstratton.com/sup...he%20Governor/