1. Check my two part article on our Home Page on nib tweaking. It tells you how to improve ink flow (and a lot more)
2. Stick to a good, proven, safe ink. Avoid reds like the plague. Some greens are also terrible as far as ink flow is concerned and some browns are also problematic. Best ink for all pens: washable blue (Royal Blue). Parker, Waterman, Aurora, Pelikan even Hero.