I'm sure this is pretty common but I am having a hard time figuring it out....
It will start when I spray starter fluid in the carb but dies immediately. Once it ran for about 20-30 seconds when I had the choke all the way closed (or open, whichever is with the lever out of its normal operating position)

2000 polaris magnum 500
New fuel pump
new petcock
new spark plug
new gas
clean filter
fuel and vacuum lines inspected, no apparent leaks
clean fuel filter
choke cable recently replaced, I believe it to be adjusted correctly

Thanks for any advice....

 

Seems like you've listed everything except the carb needle and seat. If you haven't taken the carb apart and cleaned the jets and replaced the needle and seat,could be the problem. Plus check that the spring under the top cap is holding the slide needle properly and hasn't jumped around. OPT