One thing you have to do is keep track of the washers. I always take mine apart and leave both washers sitting blade-side up. I also polish my washers using the method in JDavis' YT video. That might help as well. I haven't had an Umnumzaan for quite a while until today (just got a Startac Zaan), so I can't remember what exactly is different about it when compared to the very specific way of putting together a Sebenza. However, it only makes sense that since there's only one stand-off (unlike the Seb which has a standoff and a stop-pin), it's much easier to mis-align the scales, and if you misalign them just the slightest bit, it will probably off-center the blade. I would try something similar to the way you align a Sebenza: loosen the stand-off just a bit so the scales can slightly move but not so that they're able to separate much or falling apart or anything - not much, just maybe a quarter turn from tight - (and this is while the blade is and pivot and everything are still assembled) and loosen the pivot just a bit as well. No where the knife is completely sloppy/slack and the lock bar is making the blade rub against the scale, just enough so that everything isn't held together real tightly. Now, flick the blade out one - not real hard but with some authority. Now tighten up the standoff and then adjust the pivot to where it's acceptable for decent smoothness and no blade play. Keep in mind that pretty much any blade will wiggle a little bit, even CRK's, if you torque on them. No blade play just means no noticeable play when applying moderate pressure. You can force any standard pivot/washer style knife if the pivot is adjusted for any kind of decent smoothness. Anyway, this should ensure the scales are aligned. You just need to loosen the pivot and stand-off just enough so that the clacking open of the knife aligns them. However, if this doesn't work - do the same thing but after flicking open the blade, go ahead and close it and then tighten the stand-off, followed by the pivot adjustment. Sometimes it works better to tighten everything the knife open, sometimes it works better to still flick it open but close it afterwards to get rid of the pressure of the lock bar.
This would be easier to show you in person but I am sure you can figure out what I mean, assuming I explained the process well enough. This is part of what CRK themselves tell you how to assemble a Sebenza. It should still apply to the Umnum, though. It will be quick, too, since you don't have to take-down the entire knife, you just have to loosen it up barely. So it's definitely worth a try. But I would definitely make sure you have the washers right. If the knife has been used quite a bit, you should be able to tell the difference because the blade side of the washers will probably be quite a bit more polished. Anyway, if you have to keep trying the same things over and over, it's worth it. I guarantee that there's a way to get it back to perfect.
