Small Engines (Lawn Mowers, etc.): Briggs 16.5 twin carb problem

Question
I'am working on a mower for a friend of mine he said it has not run for the last three years.I drained the old fuel pulled the fuel line flushed it with fresh gas pulled the top off the carb cleaned it all out cleaned the jets sprayed out all the passages with carb cleaner blew it all out with compressed air reassembeled everything and put in about a half gallon of fuel got it to start but wants to run wide open but the throttle butterfly is at idle position will run slower but only with the choke almost closed throttle plate position doesn't change rpm in any position used carb cleaner looking for any vacuum leaks but nothing the owner said it run fine when he stopped using it and got his new one. i'm baffeled, did i overlook something?

Answer
Did you download the service manual?

http://www.globalsoftware-inc.com/coolerman/fj40/schematics/271172%20Twin%20Cyli

Is the governor spring installed?  Is the governor adjusted properly?  Just Google "Briggs and Stratton governor adjust" to locate the governor adjust procedures.

Can you control the engine speed if you manually move the carburetor butterfly shaft by hand?

Eric