I own a Moskva 5 its the Russian copy of a Super Ziess Ikonta, so my shutter most be a close copy of a compur, All my shutter speeds sound strong including 1 sec BUT 50% of the time the rebound (when the shutter comes to close) it sticks open this only seems to happen if I'm holding the button down all the way basically every speed becomes bulb. If I lightly tap the casing it will close. If i lightly trip the shutter and don't push all the way down it will fire perfectly. 250th and 100th always work perfect no sticking.
I've worked on a few simpler shutters in the past but I'm not sure if I want to open this without some outside opinions. Would a good flushing with Rosonal fix this? Would I have to soak the entire shutter or could I put a drop or two in the correct area and work it till it dries? Any info would help.
I think your problem is related to the B mechanism, which consists of one or two levers around the 5 o clock position. Maybe one of their cam followers is slightly misbent.
However, the Moskva shutter is not very easy to open and usually re-adjusting of the rangefinder is required. About a year ago I have posted a procedure how to open the shutter, check the archives for "moskva" and "shutter".
