I recently purchased 18 various traps from a member here. 7 of the traps appear to be new Duke 1.75s. They won't open fully. They stop about 1/2inch shy of completely opening. I've had my 13 yo grandson stand on the levers. I've stood on them, same issue. All of the other traps open exactly as designed.

Could it be something I'm missing?

If the jaws aren't opening fully then the spring levers must not be fully compressed. I've seen where the openings In the spring levers will hang up on the frame and the trap won't open fully. Tweaking the levers a bit should get the openings lined up If that's the problem.

I have one that the spring pin tends to move out of the groove in base back by the dog. Coyote catches it arms like I have to fix that after every catch. Check that because I cant set mine if that pin isnt seated in the groove.
Jim

Seen that a lot. Sucks when you're in the water.

as said,,,,,are the levers hitting the frame?
if NOT, and the frame comes up thru the opening in the levers, what is preventing the jaw tip from pivoting?

I think I'm gonna pull the springs off of a couple of the faulty ones and let the jaws flop up and down easily. This should give me a clearer picture of what's hanging up. The thing that confused me was that all 7 of the new ones are doing the same thing? I can't open and close these little traps due to disability. I'm waiting for my setters in the mail.

Cumberlands have coil spring trap setters for ten bucks that I find helpful.
just

I bought some new coild spring traps from them a couple of year ago and had to us a file on about 1/2 of the to get them to full open. It only took a couple of passes with sharp file and they worked fine.

Break out the file …

Good with your season.

Garry-

sometimes the dog side of the cross frame is lower than the jaws. The jaws would then be fully open but no way are you going to get the dog to push the jaw down far enough to engage the pan.

Same problem I had with them. Had to bend it up and then file the dog shorter.