Small Engines (Lawn Mowers, etc.): scag turf tiger with kohler 27 engine hesitation problems, engine hesitation, fuel starvation

Question
I have a 2 yr old scag turf tiger with a 61 inch deck and kohler command engine with about 300 hours of residential use.   The last 2 times during mowing, the engine starting losing power and hesitating after about 1hour of use.  The engine runs fine for the first hour but then starts to hesitate or bog down sporadically, especially when executing a turn and especially when moving the steering bars in opposite directions.  As hydraulic pressure is increased by pulling both levers in opposite directions the motor bogs down and eventually stops.  I keep the mower clean and serviced with always sharp blades.  I thought it was a fuel starvation problem and changed the fuel filter last week.  Oil and hyd. fluid have been recently changed and are full.  
I am baffled because I have never seen this type of problem before.  Thanks. RK

Answer
Hello Richard:

Send me the Model and Type or Spec Numbers Off the Engine or the Mower Model Numbers, Please. With these I can Locate the Proper Manual and Better Assist you. The Engine Model Numbers May be Stamped Into the Blower Housing (metal engine cover) Above the Spark Plug. From your Description is Sounds like; 1- Depending on the Model, the Valve Clearance May Require Setting. 2- Depending on the Model, the Gas Tank Cap May Not be Venting the Tank and Causing a Vacuum to Build and Restrict the Gas Flow to the Carburetor. 3- The Rings May be Worn or Sticking and Causing a Decrease in Compression. 4- the Carburetor Solenoid May be Heating Up and Restricting the Gas Flow to the Carburetor Jet. I can Tell More with the Model Numbers. Thanks.

Respectfully

John

PS: I am Allowed to Answer 10 Questions a Day. If you See I am Maxxed Out, then Try Submitting your Question at or Just After 8pm EST (US). My New Day Starts then. Thanks.

Respectfully

John