Could be a variety of things, the first thing I'd check is the Extruder ESteps value. There are numerous posts and instructions for calibrating the extruder, so I won't repeat them here. But that's essential. Calibrating the X and Y axes may make a difference as well.
The settings in your slicer could be making a difference, what do you have the layer height set to?
One other thing could be that you're missing steps (which could cause the spaghetti at the top,) which might be related to the amps available to each motor. The Printrboard has trim pots for each axis. Have you adjusted them at all? Are the motors running cold or hot?
I've never needed to run my PLA over 185C to get good results, so I wouldn't think you'd need to push past 190C.
It is worth making sure you're getting evenly fed filament, check the hob to make sure it's grooves are clean, if not, clean that up.
(optional Dual Extrusion) Printrbot Plus V1 [3/2013]
bed stabilizers, bed levelers, Y & X belt tensioners,
50mm fan mount, LED ring light, Z-axis screw Isolators,
Z-shaft stabilizers,optional Bowden conversion, GT2 belts/pulleys,
M8x1.25 Z Screws, Flex. Z-couplers,
RAMPS 1.4 w/ LCD,
Quick Change Extruders:
Option 1- Dual hybrid geared Wade's/Bowden w/ 3mm & 1.75mm Ubis,
Option 2 - Dual direct geared Wade's w/ 3mm & 1.75mm Ubis
Option 3 - Single geared Wade's w/ 3mm or 1.75mm Ubis
Option 4 - Single belt drive Wade's w/ E3D
MIC-6 metal bed
Thingiverse Profile: http://www.thingiverse.com/tdeagan/designs