I am tempted to suggest, when looking at the images you posted first, especially the second one, that it looks like your settings have it overextruding (to compensate for the gaps) with the idea that underextrusion is the issue. This suggest that it may not be down to the feed rate but may in fact be due to some other issue like the extruder slipping, blocked nozzle or some other mechanical feature of the printer?? but obviously we don't know.

https://www.makerbot.com/support/new...s_in_My_Prints