If like the one above, that engine appears to be an EI conversion as there is no visible mag coil. Maybe one of the ones that Ralph Cunningham did or something similar? The EI would appear to be behind that cover where the flywheel once lived. The cover should come off if you remove the prop driver hub. But just guessing as I haven't worked on that version Sachs before. Look earlier in this old thread and you can see the mag equipped version as the flywheel and coil are clearly visible.