Tom, you are correct, when the advance is all the way left, this screw grounds against a steel pin. I guess I would have seen this when I put it all back together but we were on vacation and it was on my mind at the time. Hopefully it’ll be all together in a few days. I still don’t exactly know what model it is. I see sea king midgets and I’m thinking this may be one as it’s very short shaft. I’ll post pictures when it’s finished