Well I learned a new unknown term today " cup washer" (see picture
From previous Posts I am trying to get a 1926 running and out of my Wife's garage since it has been in there a year !
Installing a new TW timer
Never done it
See picture there is a retaining pin (very small) that I believe holds the timer roller in a stationary position on the cam shaft. Question, it appears the cup washer fits over the pin to prevent it from falling out under centrifugal force but what is the purpose of the indentation in the cup washer shown in the 2 o clock position ???
Saving metal. They just stamped it a little close. Most of them have an offset in the outer rim to hold pin in place.
As Uncle Jack wrote, see the commentator brush cap (Part # 3206), next to the lock nut, usually has a bump out on the rim to nest the head of the commentator brush cap pin.
One of the things you need to check here is if your cam has the timing pin hole drilled all the way through it.If so, mark one side with some red paint or a dab of finger nail polish. Then when you get it timed,you must remember which hole side is correct.If you are out on the road and have to do some maintenance,it will serve you well.
The washers usually have two features:
1. A bump outwards which clears the head of the pin
2. A small cutaway to clear the mounting for whatever rotor pivot is welded to, or formed with, the central tube. These differ depending on whether you have a Ford, Tiger, Anderson, NewDay etc timer. I can see this at the 2 o'clock position in your photo on the left. Dan Treace's photo appears to be a Tiger.