I came from a Scarab with 5 different tanks, and a fuel log... so my Fountain with one-tank-one-motor thinking has always confused me a bit. It's inevitable that one motor consumes more, you idle more on one, etc, and then you play hell trying to get your fuel levels right. God forbid you run out on one motor. Has anyone every considered running a jumper line between each fuel line, placing a ball valve inline? It could remain closed and all would operate normally, however I could open to equalize at fill up, or should I runout on one tank. Is this a dumb idea? Any reason this wouldn't work?

You are right, it is a pain trying to equalize the tanks but connecting a jumper between the tanks won't work because the feeds have anti-siphon valves and drop in from the top of the tanks. The fuel won't flow between the tanks when you are filling up, it needs to be drawn out by a pump.

GF?

my sonic is setup where there are 2 tanks and 2 motors. I have 2 valves in the bilge that dictate which tank each motor draws from. they are usually set where port motor runs off of port tank, and visa versa. I've ran out of gas before in one motor (tank), and was able to switch the valve on that motor to run off the other tank. then both motors were able to draw from the one tank.

The only way a balance tube will work is if the tubes are connected to the bottom of the tanks and the hose stays below or equal to the bottom of the tanks. Only other way is with a transfer pump.

Yes ive done exactly what you are talking about for customers in the past. Then after each of there first summer ive ask how many times they used the system all of them answered not once thru an entire season. If your fuel consumption is off that much from side to side you should look elsewhere and fix that.