Adjusting points gap the MrMarty51 way. LOL

[Mutt]

for the 125's , take the head off and use your dial indicator on the piston crown

[Bailey]

I have an 12 mm adapter that they use to pressure up cylinder to change valve seals. I haven't tried it yet as my bike isn't running yet and I used the head off trick that Mutt suggested.Its has pipe thread on the other end so it wont be hard to adapt for a timing tool. Amazon sells this one. Lisle 20540 12mm Spark Plug Adapter

[MrMarty51]

for the 125's , take the head off and use your dial indicator on the piston crown

That is most likely the simplest method of getting the cylinder to the accurate position for setting/adjusting the timing.
Is the head gasket reusable on these engines ?
if not I`ll get one on the way.

[Mutt]

if it isnt tore. Spray it with silver paint, let it dry and reinstall it

[MrMarty51]

if it isnt tore. Spray it with silver paint, let it dry and reinstall it

I do happen to have a can of silver paint and a can of aluminum colored paint.
Silvern must be the one.