I am trying to post sections from the manual which I have as a PDF file but can’t work out how to do it!!!!!
Yes the ‘F’ mark is the timing mark and should align with the cast line at the top of the points housing as the points first open.
The points gap is 0.3 to 0.4 mm (11 to 16 thou) but is not that critical as it is when they open that really counts which is governed by the timing. This should be set when the points are at their max opening. IE when the points dog is at the top of the cam lobe.
The timing in my opinion is best set using a bulb and wire. To do this wrap a wire around the body a single filament 12v bulb such as an indicator bulb. Connect the other end of the wire to the spring on the points taking care that it does not short to anything else or restrict the movement of the points. The centre connection then needs to be fixed to earth on the bike engine for example. Remove the plug caps (to prevent accidental firing of the engine) and turn on the ignition.
Using a 17mm spanner or socket rotate the engine ANTICLOCKWISE and you will see the bulb light up when the points open. Rotate the engine again and set the points plate so the bulb first lighte when the ‘F’ mark and timing mark are aligned and tighten up the points plate and recheck adjusting as required.
I hope this answers your problem but if you have any further issues shout up