Quote Originally Posted by srs5694 View Post
Before you send it off for cleaning/repairing, sit down with it while you watch TV or something and just repeatedly cock and release the shutter. I've had shutters of that general type (I believe including a Mamiya C-series lens) that behaved as you describe, but just running them through a few dozen cycles got them working much better. I speculate that the lens had sat in a closet for long enough that the lubrication got a bit gummy, but working the mechanism a few times smoothed it out.
Yeah well, that works sometimes; but you never can tell. If it's old and sticky there's no guarantee that it won't get gummed up again quickly. Face it, the lens is old and whatever lubricants in there have lost their volatile compounds. A little bit of heat from friction can loosen things up a bit, but the gunk will start to congeal again once it cools down. Then there's the issue of years of accumulated dust and other crap that has probably worked its way into the mix. Best to get it cleand up professionally. It shouldn't cost much, and you'll have a more reliable piece of gear in the end.