I don’t think the TMD typically had a shut-off, unless it works by moving the mag lever all the way to stop where it hits a ground-out contact. (My TMD is not easily accessible right now but I’ll try to look later)
The SM and SMD models should have a kill switch on the tiller handle – many of the motors I see have these missing. (This casting is different from the twins that have the tiller mounted to a front carry handle so the twins don’t have this) It looks like this:
BTW, there was another thread we discussed the sparkplugs – maybe it was on the old board? The originals on my TMD were J-8J Champions – the modern replacements are too long and will cause the bake-o-lite insulator covers on the inside of the cowl doors to break. Best to use a vintage J-8J or use one of the shorty CJ-8 plugs so you don’t damage the insulators. Also, I recall a discussion that some TMDs may have used H-10J Champions – however all the motors I’ve seen used the J-8Js.
Did a video of running my TMD a couple years ago – if it is of help: here is the link:
https://www.youtube.com/watch?v=Mbkn97LsMoU