Pentax 6x7 qyestion?

I went ahead and traded with a local shop for a Pentax 6x7 and 90mm f/2.9 lens. So far the way the camera handles is great but there is an issue.the first roll of fill had over lapping frames and some that were too far apart.
Inside the is a pressure plate to change the pressure for shooting 120 or 220 film. there is also a small selector on the right side that switches between 120 or 220. the selector is self explanatory but it sticks up like a mushroom and it looks as though it should pop back down into the recess. If this selector was an issue could it cause the frame spacing to be wrong?
Another thing I noticed is when I load the film and advance the fil to the "start make on the film, it completes the winding stroke closer to the 220 than the 120 mark.

There is a protective collar around my selector, that you do not seem to have.

However I don't think that the selector position should make a huge amount of difference. My understanding of it is that it sets the number of exposures in the exposure counter.

The counter is moved by the movement of film, inside the camera. When I dry fire the camera, the counter does not advance even though I can wind the advance.

However, I am not a Service expert. I do have a copy of the service manual if you need diagrams, etc.

stradibarrius said:

Another thing I noticed is when I load the film and advance the fil to the "start make on the film, it completes the winding stroke closer to the 220 than the 120 mark.

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You shouldn't complete the winding stroke with the back open. Line the film arrow up with the 120 arrow then close the back. This is always part way through a wind cycle. With the back closed then advance the wind lever until it stops at one on the counter. That will get you ten frames to a roll. The pressure plate setting is just to change the pressure between 120 and 220 - I'm not sure if it could cause overlapping. The little selector on the edge just tells the counter what length of film you have in. So my guess is that it might be another problem that requires a service.

The camera looks mangled, no more so evident that the 120-220 clutch switch — what has been going on here??
And that might be the problem with the frame overlap: the clutch/gear that defines the length of travel (and thus the number of frames that differ from 120-220 film). The switch should be repaired and exposures tested again to ascertain correct frame spacing.

I think it would be best to take it back. Sorry to say, but this gear is not worth the hassle. There are tonnes of Pentax 67 bodies out there that are still working fine.

AFAIK the Pentax 67 does not fire unless film is loaded. The 120/220 switch must be set correctly, because the trailing backing or glued paper strip of 120 film can cause damage to the shutter if you keep on firing it beyond ten frames.

dorff said:

AFAIK the Pentax 67 does not fire unless film is loaded.

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That's right. To circumvent, open the back and put the body on a table. Now, with the right thumb, push down on the central part of the film counter, turn it and hold it (i think counterclockwise, don't have my body at hand right now). The frame counter should advance past 1. With the left hand, close the back door. You should now be able to dry fire while advancing the frame counter as well.

Christian