Pouring foam but it isnt my line...

So I poured my first legged beer last weekend. I was getting a lot of foam but it did go away pretty quickly. My line is 12' of 3/16" tubing. My faucet was wide open when I poured. When I poured I could see bubbles coming right from the keg. I have a few thoughts on this and wanted to get your opinions...

1) my line wasn't cold enough because I had it out. This I can test by attaching to my new keg and pouring a beer since the lines have been in the freezer.

2) it looks like my dip tube pushes down on the bottom of the keg making the opening smaller. This could cause bubbles to form and go through the line. This I can fixed by trimming a little off the dip tube.

3) posts and pop-its don't match? Is this possible?

4) carbed at 12psi for 3 weeks. Could it have been over.carbed?

What do you guys think is going on?

I will go home and try my new keg to see if it happens. This is a different beer in a different keg.

4) Depends on your temp. I had my beer carbed at 12psi, but since the fridge is at about 38F, that was too much damn co2. I turned it down to about 8.5, and it's perfect.

Brewheads has a pretty good calculator to determine psi at a particular temp, but I think their numbers are a bit high for my tastes.

Line balancing is not just to make sure the lines are long enough. If your lines are too long, the carbonation will come out of suspension in the lines (is that happening here?). How long does it take you to pour 16oz?

My temp is set to 44 so I think 12 psi is right around where it should be. It could go + or - 1 but that shouldn't make a huge difference.

I think if my line was too long, I wouldn't see the bubbles start forming at the keg.

I may turn it down to 10 psi to see what happens. I may also cut just a little off my dip tube so it doesn't touch the bottom of the keg.

I feel like pouring a 16 ounce takes a normal amount of time but I can time it.

EDIT: My reg was at 8 psi after pouring a few ounces so I put it back to 12psi and poured 16 ounces at 14 seconds. It seemed to be coming out at a good rate. I think right now it is under carbed because it wasn't set to the right psi but it has only been on CO2 for a week.

It could indeed be the poppet not seating right in the post and causing turbulence.

Check the dip tube o-ring.

Wasn't paying attention while reassembling a keg one time and forgot that important little gem; bubbles out of the keg and almost nothing but foam. Took the post off, and...

I did remember to put all them back on. I think it is the poppets. My keg now pours fine...no head but that is another probably lol