Can someone please clarify the purpose of the small brass(?) button below the front cover on the subject magneto please? The parts diagram states that it is a 01080 Stop Unit, so I would think that the small 'tit' on the end should be depressed to short the mag and stop the engine. Is this 'tit' meant to depress please, as mine doesn't. I have given light persuasion with a rubber hammer but don't want to break it.
Thanks in advance. Oscar.