Anyone know why my montblanc cartridge pen always blocked?

Montblanc makes stunning pens. Please give us a picture of yours. The size of the Nib (point of pen) and how frequently you use it can impact on this. Fine Nib can keep from drying longer...I don't remember if my Medium or Bold Nibs dried out faster than each other. But when using it continuously (like they were in the olden days) they are like butter. It takes a while for a Nib to break in, so if the pen is new, or just new to you, try writing with it a lot. My first Montblanc was a Solitaire Doue with a broad nib...the ink flowed like paint and it was heaven to write. I wrote the whole first draft to a screenplay with it. The Doue meant I could use it with carts or with the pump system. Are the cartridges Montblanc or an after market? I had several that used cartridges. Just signing a check now and then isn't enough to keep the Nib from drying out sooner than later. Ironically the best pen (in my experience) for taking weeks and weeks to dry out is a cheap little pen from Germany, the Kaweco Sport...simple brass Nib...about $25 on Amazon. Short and easy to tuck into your pants or jacket pocket. Nothing fancy about it. But their cartridges I think suck and so I buy the Montblanc carts for it. Good luck.