No desire to argue with anyone on the internet - BUT my experience disassembling (and reassembling) dozens of za50 transmissions is that the best way to take the stuff apart is with an impact and your hands only. Here are my "tips and tricks." Maybe I'll make a YouTube video soon.
I first use bits from a manual impact driver in a cordless driver to pull the trans cover hardware off.
I hit the cover with a rubber mallet to get it to pop off. (I drain the oil from the cover, not the drain bolt. I do not remove the drain plug first. My experience is that you cannot guess how much some previous person tightened it, and if it does not leak, I don't want to pull any bits of aluminum case out with the steel drain bolt and cause a new leak in some customer bike / on my shop floor.)
When I do the 15mm reverse thread nut, I do not use the socket on sprocket trick any more. I just hold the gear cluster with my left hand and apply steady force towards myself while applying short bursts with the impact. If the battery impact does not work, I swap to an air one. This way there is no pressure on anything. I've gotten to the point where I can pull the impact off the moment it gets it loose. Then I turn the complete assembly with nut and barrels off the rest of the way by hand and keep all of the barrels in place. BUT as Jay mentioned, you can totally also just take the barrels out first.
For the larger nut, I use a super deep well 24mm on the impact and hold the clutches with my left hand again. I take the spark plug out so there is no compression on the top end. I don't pre-flatten the lock washer. I just quickly hit it with the cordless impact. (This one is never stuck like the reverse thread 15mm, so you won't need to use air). The quick spin flattens the lip of the lock washer "just enough," to thread the nut the rest of the way off with your fingers without mangling the lock washer nor putting any pressure on the clutches. It also preserves the bend in the lock washer enough to re-bend it the same / keeping it looking factory when putting it back together.
I also use the manual impact driver bit in the cordless impact to pull the flat heads out of the second gear to replace the pucks.
I'm not saying that this is the only way to do it BUT if I start with the tools laid to start out, I can have a za50 trans fully apart and laid out in order, completely in tact in like 5-7 minutes depending on how agreeable every part is.
I usually take a while for assembly because I thoroughly clean every part; check for weird markings that indicate things like rubbing or over heating or previous work; and wiggle and manipulate every little thing checking for play.
Obviously using factory tools will work, as will other community tips and tricks. I'm just sharing what has proven to be my winning formula having done dozens of these.
Good Luck! (edited)