An embodiment of an open-irrigated catheter system comprises a tip section, a distal insert, and mapping electrodes. The tip section has an exterior wall that defines an open interior region within the tip section. The exterior wall includes mapping electrode openings and irrigation ports. The exterior wall is conductive for delivering radio frequency (RF) energy for an RF ablation procedure. The irrigation ports are in fluid communication with the open interior region to allow fluid to flow from the open interior region through the irrigation ports. The distal insert is positioned within the tip section to separate the open region into a distal fluid reservoir and a proximal fluid reservoir. The mapping electrodes are positioned in the mapping electrode openings in the tip section.