i have a 146 and use MB ink (sepia) - a great pen that writes well.

in my smythson notebook which has featherweight paper (50gsm), it really is constructed well enough so that there is no blood or feathering. great.

one problem that i get from time to time is that the pen stops wanting to write, as if it's dried up a bit. it seems like the featherweight paper is slightly waxy (?) and inhibits the pen's ink flow sometimes. have never had this problem on any other paper.

anyone had similar experiences or can suggest a reason for this happening?

I have had the problem you describe on onionskin paper. Is that similar to the the paper you're using? One suggestion of its cause was that it was the oils from my own hand leaning on the paper as a wrote. I'm not sure if that was entirely the case and I have never fully resolved the problem.