Small Engines (Lawn Mowers, etc.): Deere 345 Stalling after 30 min, hose clamps, screw type

Question
I have a 1996 Deere 345 with the 18hp - FD590V - engine. I can mow for about 30-45 minutes then the mower shuts down. I can get it running intermitantly by choking it fully. If I just let it sit for a couple minutes I can get it to run just like nothing is wrong, after about 15 minutes it will stall again. I get spark, the fuel apears to be flowing fine. I have removed and cleaned the float bulb off the carborator a couple times and it seems to fix the problem for one mowing, then it all starts again. I have also replaced the fuel filter and fuel line. I have cracked the fuel cap incase it is causing a vacuum and that doesn't help. I have heard that these engines cam with a plastic cam. I bought this mower used and I am not sure if the plastic cam was changed or if it would cause this to happen. Is there any way to check the cam without tearing the whole motor apart? I have also removed, soaked, and blew out the carborator with no sucess.  Could this be something with the ignition?  I have checked for spark as it is acting up and it is there on both cylinders, but as soon as the mower stalls I can always restart it with the choke on for a couple moments.  Any other suggestions are greatly appreciated!
Jeff in Iowa.

Answer
Hello Jeff:

If the Fuel System has the Spring Type Hose Clamps, then Replace ALL of them with the Screw Type Hose Clamps. When the Spring Type Hose Clamps get Older, then Tend to Weaken and the Heat from Operation Makes them Even Weaker and Sometimes this Causes a Leak on the Suction Side of the Fuel Pump. Have you Checked the Pickup Tube in the Tank? Is the Tank Clean of Trash/Debris? If there is Trash in the Tank, it will Slowly be Sucked to the Pickup Tube and Restrict the Gas Flow to the Engine and Cause the Problem you Described. As Soon as the Engine Quits, the Gas Back Flows and Flushes the Trash Away from the Pickup Tube. When the Engine Restarts, it will Run Until the Trash/Debris Restricts the Pickup Tube Again. I have Seen the Ign Module/Ign Coil, Igniters and Pulsing Coils Cause the Same Problem. For JD Mowers you Need to Remove the Pulsing Coils, Igniter and Ign Coil and have your Local JD Dealer Test them for you. Usually they can be Tested for Little to No Cost. You can View a Breakdown/IPL of the Engine and Mower at this Site Addy, http://jdpc.deere.com/jdpc/servlet/com.deere.u90490.partscatalog.view.servlets.H... and Enter the Model Numbers (345) and Click Find. Then Select your Model from the Search Results Area. Then Select the Sectional File. Then Select the Section of the Mower you Wish to View Online. If you Hit a Snag or this Does Not Correct the Problem,  I am Here if You Require More Assistance. Hope this Helps. Let me Know What Happens, Please. May the All Mighty Bless You and Yours. Thanks.

Good Luck

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