Small Engines (Lawn Mowers, etc.): JD 318, sectional index, seat area

Question
I have a JD 318 rider w/Onan V-Twin.  It ran fine last fall when I put it to bed for the winter and now...It ran fine for the first few minutes then...sputtered and died.  I replaced the fuel filter and I know it's getting fuel through the filter now...it stays full.  The problem now is it will run fine at (idle), but when you run full throttle, it will only run about 45 sec - 1 minute then...begins to die.  If you pull the throttle back to idle (quickly), it will stay running just fine...push back to full throttle and the problem repeats.  I've checked the choke (manual) and replaced the filter like I said earlier.  Now...I'm stuck.  Any help would be greatly appreciated.

Thanks,
Bob

Answer
 Hello Bob:

 If the Fuel Pump Is Good, then the Cause is Most Likely the Carburetor Float is Stuck Half Open and Only allowing Enough Gas for Low RPM Into the Carburetor. Remove the Carburetor Bowl. Spray Carburetor Cleaner (Use the Plastic Tube for Precision Spot Spraying) and Spray the Needle and Seat Area. Gently Move the Float to Work the Varnish and Cleaner Together. When the Float Drops Freely After being Lifted with your Finger; Reassemble the Bowl and Run the Engine. If This Did Not Correct the Problem, then Remove, Disassemble and Soak the Carburetor Overnight in Carburetor Cleaner(I use Gunk). Then Blow Out the Passages with Compressed Air and Install New Kit. You can View a Breakdown/IPL of the Mower and the Engine at this Addy http://jdpc.deere.com/jdpc/servlet/com.deere.u90490.partscatalog.view.servlets.H... and Enter the Model Numbers 318 and Click Find. Then Select your Mower from the Results Area. Then Select Sectional Index. Then Select Fuel and Air. Hope this Helps. I am here if you Require More Assistance. Let me know what Happens, Please. Thanks.

 Good Luck

 Respectfully

 John