Photo souse from Chinese forums.

At first, please set the flywheel to 6.

Then, see photo

Release the screw. Turn the distributor to left side. BUT DON’T release too much, you should feel a little tighten, that should be better.

And now, turn the ignition switch to power on. Then, turn the distributor from left to right slowly.

When, the ignition point open, and find the spark. That is the correct timing!!! Tighten the screw. Job finished.

You can try some times to make sure that is the ‘correct timing’.

And if you cannot find the point, release this screw, turn the distributor itself. And reduce again. TURN slowly and shortly.