14V at the end of a 130M 24AWG (presumably) cable run is actually quite good. The voltage drop is quite normal over that distance, but it SHOULD be sufficient as the RB's SHOULD operate on 12V.
As others suggested, I would also recommend trying a 30V PSU. Just to be safe. My guess however, is that you have a 24V/1A PSU, and the 1A isn't providing enough juice to power all 4 devices. Try a 30V, 3A or 5A PSU. It may, or may not work.
The problem with daisy chaining things like this, is that the PoE out on all these devices, limit the amount of current on the ports (and for very good reasons). Personally, I would run power and Ethernet separately here, and not use POE but rather just tap a steady 24V off the power cable at each device. You running a very high risk here that the RBs closer to the PSU (thus pulling more current), could actually burn out.