Help with getting MC-9 to run

[Michael Drechnowicz]

I am trying to get my MC-9 with a flatback carb to run to take to a kart event this month. It starts right up with part throttle and choking the carb. It runs well for about 5 seconds and then starts to die like it is out of gas. If I choke it (cover the carb) it picks right back up. I do not see any bubbles in the fuel line so I don't think there is an air leak but I replaced the fuel line anyway. Changes to the carb adjustment screws do not help.

Engine was last run about a year ago and ran fine then.

Any suggestions for what to look for?

Thanks,

Michael