I had/have the same problem with my epson740 every now and again,
It's probably the black ink tray that is overfilled as like mine its getting on a bit
What i do is press the button like you do when you want to change a cartridge, then move the carriage further along, i then get some cotton buds dipped in water (only dipped) and use several to get the excess black in the ink tray, which on mine is situated in the far corner, bu**er to get to

, then i use dry cotton buds to get any excess away and clean the rollers, feed a sheet of paper through a couple of times and that normally clears it for awhile.

Funny enough i have been reading up on the printers lately as i'm gonna change mine after christmas, i wanted a canon i865 but they seemed to be discontinued now, so i've decided on the Canon ip4000

but will check Kremmens one 1st, the good thing about the ip4000 is you can change indivigual carts when 1 runs out rather than the whole set like some.