Curious if others with a 260 backhoe could check a couple things.
With the bucket in the air (no load) and you are curling, or moving the dipper stick, the boom is unable to lift at all.
However if you have some load on the bucket or dipper stick then the boom can lift some... like when digging.
Seems like a flow problem, but even with RPM's maxed out it acts the same.
To answer others questions... my 260 can lift the tractor off the ground provided the bucket is fairly close to tractor. It can lift it with Boom or DipperStick.
Also curious the purpose of the 'float' position on the Boom. I used float a lot on a FEL and understand it's purpose... just don't see a purpose on the backhoe boom.