Locating dimple on timing gear

[aermotor]

Originally Posted by Forddan

I had in mind that once the distributor was timed you can take it out and insert it again any time later (months??) and will keep the timing. Now I know this is incorrect.

This is not incorrect. The backup distributor if set up properly can run forever as though it were new. Human hands are the only thing that can change a mechanical junction (which timing is) whether dist. #1, #2 or even #12 back up.
Pull any of the 12 back up distributors turn the engine as many times as you want and it will still be in time when you drop any of the distributors back in.
Katy is correct if we talk about other worn parts.

John