I just bent my fuel line yesterday (5/16"). To make a 90, I used a spool-type bender ($10 at the local NAPA) and bent it about 60*, then moved toward the apex of the bend a little, bent another 5* and did that a couple more times, working away from my original bend, till I finally got a 90* bend. Granted, the radius of that bend is larger, but it doesn't have any kinks.