Hello i just puchased a slimline skywriter pump and was using it the other day for the first time and it was in a 20 oz tank, it kept losing prime when i did even a fast roll or a loop. i used the yellow gasoline line inside of the tank, clunk was heavy one but not the biggest one. should a guy use some of that black line that is more flexable or what are you guys doing. i have the check in the line for the exhaust so it can flow only to exhaust, line out to pump and vent line open to outside fuse just like the instructions say but i keep losing prime. ***. Help would be much appreciated.