Worn out slide
 

I wanted to lean out my bike a bit. Running way too rich on the low end, lean on top. So I broke out my jet kit. took out the 50 pilots replaced with 48 pilots dropped the needles one clip and increased the mains to 175 front and 178 rear. Set the mix screws at 2 turns out.
When I pulled the slides and found that they were severly worn on the bottom leading edge. Swapped the slides with a set I had in a spare set of carbs. Took out for a test ride. Feels great. Pulls awesome just a few pops at mid on deceleration. Going to lower the needles back to where they were.

Anyone else ever have this problem?

I actually did, but I found that the problem was a rotated diaphragm so it was creating torsional differences on the slide itself and it was rubbing on the bottom of the slide with no movement.

I would refit the slide diaphragm on there, bolt it down and "blip" the slide a few times. If it sticks at all or goes down slower than it should, then it's difficult to diagnose.

I polished mine with a plastic polish and it turned out just fine, in conjunction with cleaning the slide carriers with carb cleaner, it turned out just fine.

You might want to check the small foam sub-filters in the airbox. If they are worn out or really dirty they might be letting dirt into the carbs which causes this problem. ;)