As promised, I tried out my bottle of Yama-Dori in various Lamy fountain pens (1 Safari, 1 Vista, 2 Al-Stars) using various Lamy nibs (B, M, F, 1.5mm italic), with both piston converters and syringe-refilled cartridges. I also tried it in a Pilot Metropolitan with a Pilot M nib and aerometric converter, as well as an old Sheaffer with a piston converter and a fine (I think) gold nib. I didn't try it in my Noodler's Nib Creaper.
No matter which pen or nib I used, or whether I used a cartridge, piston, or aerometric converter, the long and short of it is that my sample of Yama-Dori dries out extremely quickly and is a huge pain to get going again once it's dried. In some cases, leaving the pen uncapped for a mere 30-40 seconds (a pause to contemplate while writing) was enough to require half a dozen strokes just to get the pen going again, and often it would skip a lot too before finally writing normally again.
I also noticed that it's very clingy. It took a LOT of flushing with a syringe to clean the last few drops of Yama-Dori out of two of my Lamy cartridges.
Note that I've used several other brands and colors of ink with most, if not all of the pens, cartridges, converters, and nibs I used for testing Yama-Dori. I haven't had problems with any of them.
As far as I'm concerned, the rumors about Yama-Dori are 100% confirmed, and I will not be using it except in my Pilot Parallels. Even then, I'm worried they may need a lot of cleaning once I've used the last of the Yama-Dori they're filled with.
Maybe there are only some bad batches of Yama-Dori out there, and I was unlucky enough to get one. Who knows?
Edited by Blaine, 16 February 2015 - 01:38.