Manual for China USD forks

[Kivi]

Hi, is there a service manual for china USD forks like on the photos?
I need to change oil in my forks and wanted to follow the procedure and specifications from some reliable source.

[humanbeing]

http://www.chinariders.net/showthread.php?t=10266 is similar BUT his are CM-2.

[Kivi]

Thanks, HB. Mine are CM-2. But I also have CM-1, which I am currently disassembling to learn the procedure etc. But they are different.
In the bottles is the amount of oil i took out of each fork, 250ml approx.
But mine forks (still on the bike) are a little different, and are about 20-30mm longer and have 20-30mm longer travel. I see they do not have the "spacer", resting on the washer, at the top of the fork (pic 2 on previous post). I always wonder if this is from factory, or someone improvised something.

Second question is if there are any adjusting add-ons for these forks, like additional preload adjusters or rebound or anything.

[Kivi]

OK. let me write some differences between CM-1 and CM-2.
First, Inner (bottom) tube, outer (top) tube, top bolt - cover and bottom bolt are all the same dimensions on both forks.
Springs are the same dimensions, height, width and thickness.
Cartridges or dampers are totally different, jet, again, similar. On one of the forks damper cartridge is simply upside down compared to other fork. On CM-1 damper rod is at the bottom of the fork and the cartridge is at top, while on CM-2 rod is at top and cartridge at bottom. So, this plays a role in oil quantity, so CM-1 requires about 300-330ml, while CM-2 about 200-220 (I have it at 220mm right now). Cartridges alone have different travel. I'm talking about travel when removed from the fork. CM-1 has about 18cm travel, while CM-2 has 26cm travel.
I do not fully understand how these cartridges work, but considering the differences in cartridges there must be some operation differences; CM-1 looks like it could be something like dual chamber fork.
Preload spacers are both same all dimensions with smalll differences in their washers and inside.
One big difference is that CM-1 has 25mm spacer at the top of the fork. This spacer does not influence spring preload nor fork travel. It simply rises the fork for 25-26mm.