Motorcycle Repair: engine revving too high after carbs cleaned, google search, occurence

Question
I just cleaned out the carbs on a 1966 Yamaha yr2c that was sitting in my father in laws garage for the past twenty years.  I got the bike to start but it revs up way too high.  It is in the 4500+ rpm range when I start it.  I think that I may not have set the floats right in the carb when I put it back together.  I am writing too see if this is a common occurence and if there is an easy fix.

Answer
David, I had never heard of a '66 Yamaha YR2C until you mentioned it. I did a Google search and came up with a few images, it looks like a neat bike. But it is a 2-stroke and as I have very limited knowledge of this type of motor, I won't be of any help to you.