Kawasaki FH721D-ASO4 GOVERNOR?

I just put a new head on a Kaw FH721d-as04. I can't get the thing to pull a load. I adjusted the governor per the manual, but it would not rev up. When I push the governor/throttle linkage forward the engine revs. I moved the governor shaft to allow it to run faster. It will with no load. Start mowing, no power. I'm at wits end. Any suggestions?

Thanks,

Bill