- Check the nib/feed alignment - Make sure the nib/feed are fully seated - check nib alignment - see the "baby's bottom" discussion in the 13 tips video - some pens have a weak feed, it may need to be replaced - some converters won't feed inkGet a loupe! (I have a nice microscope).
Feeds may be made from ebonite or ABS. Ebonite tends to give more ink flow and may be what you need with a flex nib.
Tom's Pen Info / tom@mmto.org