Quote Originally Posted by noiseboy72 View Post
My experience is that 3mm works better over Bowden printers - less flex in the filament. There are also a few filaments only available in 3mm - but far more only available in 1.75mm!

You will be spending around $90 to replace the hotend, extruder drive housing and tube / fittings, so you need to ask yourself if this printer remains a bargain.
^^That... I place the most prominent reason in bold but all of it is true. I think the bowden system while has and inertia advantage it also has so feed/retraction limitations.