Bloody hell we have a ton of experience with this. I've spent more hours chasing this...
First step is to get the service manual, open to chapter 8, section 15 & 18, and make sure everything looks like that. After you've done that to very little avail, turn the bars while watching the cable, maybe have someone put the tank on and off while you watch for ANYTHING that could possibly bind. And it looks like it should be tied up more but I've had better luck with letting it run free-ish (to a point-you want to keep it away from hoses and wires).