Jim, although I probably would of agreed with you prior to hooking my system up, I felt somewhat lame after being given a set up that is just with a tee by a local marine professional that's been around for quite a bit. I have a 115 and a 8hp that has a 5/8 fuel line. After rigging it up, there is no such air being lost or fuel being sucked out of either motor. I actually can run both motors at the same time with no issues what so ever. I've never had to squeeze the bulbs when I stopped trolling and started the big motor. Maybe a misconception? I'm not arguing just explaining my setup. Tight lines Sent from my iPad using Lake Ontario United