Copal #1 shutter much too fast at slow speeds

[seezee]

Any tips on repairing a Copal #1 shutter that fires too quickly at the slow speeds? It is only marginally slower at 1s than it is at 1/400th second.

I know how to take one apart for cleaning & lubrication but this is beyond my experience.

[BrianShaw]

The slow speed escarpment is either defective or has been replaced incorrectly.

Or, the speed ring has been incorrectly installed.