For those who found a copy of the service manual but does not know what the hell its talking about regarding shutter speed adjustment. Here is a version that make sense for amateurs.
Note: Before you take your frustration on the shutter speed cam. Make sure the shutter is indeed cleaned and lubed professionally, and the blades is free of any kind of oil. And remember, under most circumstances, you only have one shutter speed cam on hand, in another words, this one is not for amateurs.
First you should be able to strip everything off from the front until you can see the shutter, I’m not gonna show you how, it’s pretty much self explanatory. The shutter speed cam sits right on top of the shutter unit. Snip the wire at the end that connects from the body to the meter. It is optional, but it will make it a lot easier, solder it back when you’re done.
The manual saids ” Strike it with a punch to make it faster, and scrape it will a file to make it slower” That’s where its talking about. Put the cam back and you will see it moves a gear up and down. With the gear all the way up, it will be the fastest shutter speed. The fastest speed 1/500 is located on the left, to B on the right. Be careful and think it through before yous tart striking or filing it, observe what else the ring moves around.