Strobing a varitronic

[Zanele]

Motor's running after complete build with almost all new components.

It's my first Lambretta, so forgive me if I ask anything stupid.

I'm trying to strobe my ignition (varitronic) and it seems to be 24 degrees at fast tickover. As I rev it (nervously) the timing appears to be static until around 4000 rpm (engine speed judged by ear). Then the mark disappears round to 180 degrees out.

I assume that this is because there are 2 sparks per revolution, but how do I strobe it correctly? This seems especially difficult as I don't have a rev counter.

it's a GT186 with Ancillotti clubman https://mechanicguides.com/best-timing- ... -ignition/ , so not particularly revy motor. I'm guessing it will max out at around 7500rpm.

Advice please?

[Puffs]

Following a moderator choice that is IMO biased and flawed (someone posting aggressive personal attacks is rewarded, while my technical posts are removed), I have withdrawn from this forum.