Craftsman 5.5hp Randomly wont run?!

[CraftsxMan]

hello i have a craftsman 5.5hp mulcher..it ran fine last season and did so this season until recently. It will run for a solid 20 minutes then just die out, when i re prime it,it starts and runs for 5 seconds. only until i re clean the carb itll run for 20 minutes and do the same thing over and over.
Things i have done to it:
-change spark plug
-clean carb 5 times
-empty out gas tank and clean
-use a new jerry can with fresh gas
-replace fuel line
-new air filter

When i clean the carb i use carb cleaner and take apart everything , even cleaned out with a needle the little fuel jets on that bolt.

my mower is this one

 

[CraftsxMan]

bump bump bump bump bump bump bump bump bump bump bump

 

[Rivets]

You haven't cleaned the carb throughly. Go to the local repair shop and get a needle and seat repair kit #631021A. Remove the carb and disassemble. On the side of the carb is an idle jet, under the black or white plastic cover. Take a small pick and remover this cover, unscrew the jet. This jet has a small oriface in the end and will plug easily. To clean this use the spring wire on the float needle valve. Make sure that you can get it through at least a1/4". Spray carb cleaner through when you are done. Please read the following thread, which fill help in reassembly. I know it is for a Walbro carb, but the steps are almost the same.

http://www.lawnmowerforum.com/small...g-idle-then-stall-under-load-please-help.html