Small Engines (Lawn Mowers, etc.): toro engine reving high, spring problem, model command

Question
I have a Toro Z, Commercial Model, Command Pro 23Hp Kohler, 60 inch,and when I engage the PTO the engine revs too high. Any ideas? Also any ideas on downloading a service manual for this Thanks  

Answer
I know toro has a service manual for this unit and will be based on your model and serial number I'm fairly confident that it is downloadable the engine manual would come from the engine manufacturer and you would have to check their website.  

For the other party your question I need more information.  Normally it is the opposite PTO is engaged the engine bogs down because of the load on the engine.  You say the engine over revs. It could be a governor spring problem or something with the governor internal to the engine. if over 3600 RPMs I suggest having your engine inspected before you use it too much longer because it will destroy a connecting rod in the engine. You could engage the PTO and have someone watch the governor arm. when the load is put on the engine the arm should move to compensate for the load if it's not moving and staying put then you have a governor problem. the best way to attack this is adjust the gov per the current engine manual. if it still is doing it then remove the engine open it up and replace the governor hope this helps.