Small Engines (Lawn Mowers, etc.): Toro Clutch blade malfunction, clutch style, blade control

Question
I have a 6.5 hp Toro Super Recycler mower with the clutch style blade Model 20475 Serial 6913394. As soon as the mowing gets a little tough, the blade stops turning even though I have not released the control handle and the engine governor does not speed up the engine.  I have adjusted the blade control according to the factory manual. Is there a problem with the blade clutch and why doesn't the governor increase the speed of the engine.

Answer
It most likely is the blade drive belt, they become glazed over after time and begin slipping under a load. I'm pretty sure this model uses a belt along with the clutch. As far as the engine not speeding up, thats because it doesn't know it is supposed to, with the belt slipping the engine actually isn't under a load, as long as the belt is slipping there is no load...make sense?......Tom