Yes, that would make sense. The only other thing I can think, because of the angle the brake hose comes off the master at, there's a big high spot in the line, so it wouldn't surprise me if there's a big air bubble trapped in there. The weird thing is though, that I don't really have to use much force at all, it's almost too easy - I grabbed a handful on my first ride when I bought it, I definitely wasn't expecting it to stop as quick as it did!

Either way, I've been doing some more searching and it does appear to be the PS 11. Thank you again for that! I hope a rebuild kit won't be so hard to find if/when the time comes!

On the subject of rebuild kits, I don't suppose you'd happen to know where I could find pistons & seals for the XTX front caliper, as Yama don't seem to sell them? I've read on the forum of the XTR and XTZ calipers being the same as used on one of the BMW GS models, but I couldn't find anything about the XTX caliper.