Hi, I have a second Rowena saw conversion of about 55~60cc. They are based on the old Stihl 08S saw / TS350/360 disc cutter. This one has had the crank turned to accept a Super Tigre 2000 style prop driver, complete with brass collet.

I want to convert back to petrol and have fitted a pickup, magnet and insulator. I'm just wondering about pinning the collet in some way in case it slips and alters the timing. Should I bother? what is the easiest way of pinning if it is required? I only have common hand tools and a pillar drill, so don't want to mess-up the good fit of the components, or stop the collet from binding up and running true.

This is it:-