My poulan pro 500ex runs until I try to go forward or backward then it shuts off

Jason, Belt routing for Poulan Pro 500 on page 18,19 and 20 of attached manual. Check the attached links,instruction and guides, Good luck
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User Manuals
http://www.poulanpro.com/ddoc/ppoo/ppoo2012_aaen/ppoo2012_aaen_pb22h46yt_532448351.pdf
poulan pro 500ex belt diagram Google Search

if engine runs but does not provide any movement in wheels or deck , id ck the drive belts 1st , there is a separate belt for drive and deck , its possible both of these are broken or slipping badly

Check the brake caliper; it may be struck

with a peice of hose and siphon it out

A couple of ideas, it could be a fuel tank breather issue, when it starts to die just try loosening the fuel cap, if the saw picks up again you will need to change the breather, the only other thing i can think of is a bad ignition that is breaking down when hot, the only aswer to this is to replace the ignition unit

Check to see if you have the chain oriented correctly - it is east to put them on backward without realizing it. Th3e teeth should point forward, with the anti - kickback lug in front of the tooth. Let me know if this helps!!

adjust the clutch cable

The chain is directional, only cuts one way. If a new chain won't cut, it must be on backwards.

This is a lawn mower catagorized as a chainsaw. We don't answer lawn mower questions ands you don't cut down trees.

SOUNDS LIKE YOU FOLLOWED ALL THE CORRECT PROCEDURES. TRY TO GOOGLE SEARCH YOUR POULAN PRO MODEL #, I'VE HAD ALOT OF LUCK GETTING MANUALS AND DIAGRAMS FROM THERE. GOOD LUCK!!!