Kz650 Cases not spliting!

I removed all of the bolts, even the hidden ones under the oil pan and I can't get the cases to fully separate. The cases are split like crazy, but it seems like the pistons are preventing the upper case from coming fully off. I split the cases on a backup motor last month and they came apart no problem. I can remove the gears, I can even lift up the crank but the cases will not fully come off. What am I missing?

when i split my cases i thought i had bolts still in......then i let it sit for a half hour....i came back out and it "spread" more....then it fell apart. recheck your bolts......then pry apart in correct areas.....dont be too rough....it might just be the gasket holding it. good fortune.