String Trimmers

We have a husqvarna trimmer (323L 325C X-series), which i had to replace the air purge, so i marked the lines as to which line was top & bottom...but my husband said that i marked them wrong when i took them off. It starts ok and runs for about 5-10 minutes then dies and won't restart. It acts like it has run out of fuel, but there is plenty. I need to know which line goes where so it can be corrected!!! The operator's manual does not show this procedure.