Small Engines (Lawn Mowers, etc.): Craftsman dies after blades engaged, craftsman riding mower, briggs stratton

Question
QUESTION: I have a 19.5 Craftsman riding mower with a Briggs & Stratton 19.5 HP I/C Platinum engine.  I just performed my spring maintenance on it.  I replaced the points, changed the oil, put a new oil filter in and checked the tire pressure.  It cut fine for about an hour.  After that, when I engage the blades, it dies immediately.  If I just try to drive it without the blades engaged, it has very low power and is very jumpy.  I assumed the carb after reading several other posts on here, but I can't find it.  Can anyone tell me where the carb is on this model and how to check it.  I have checked the Sears parts web site but the carb is not in any of the schematics.  I appreciate any help.
ANSWER:   Hello Joel:

 Send me the Model Numbers Off the Mower and I can Locate a Breakdown/IPL for you to View Online. The Breakdown/IPL will Show the Engine and Carburetor. Thanks.

 Respectfully

 John

---------- FOLLOW-UP ----------

QUESTION: Thanks for your reply John.  I have found the carb.  Can anyone tell me how to check it?

Answer
 Hello Again Joel:

 Depending on the Model Mower and Model Engine, it could be Several things. 1- The Fuel Shut Off Solenoid in the Base of the Carburetor. 2- The Valves have Moved Out of Adjustment. 3- A Bad Seat Switch. 4- A Bad Interlock Relay. 5- Carburetor Requires Cleaning. 6- Gas Cap Not Venting the Tank Properly. 7- A Clogged Fuel Filter. Go to this Addy http://shop.briggsandstratton.com/BShopProductListingPage.asp?rsvp=0&PARENTID=0& and Enter the Model Numbers Off the Engine. Enter the FIRST 4 Type Numbers Off the Engine. Now Click Search. Now Select View PDF. This will Download a Breakdown/IPL of the Engine for you to View Online. Hope this Helps. I am here if you Require more Assistance. Let me know what Happens, Please. Thanks Again.

 Good Luck

 Respectfully

 John