Mercury 3.5 surging and very running rich I think

[Tiki91]

2018 Mercury 3.5 four stroke outboard surging And running very rich no fuel mixture screw on carb hard starting also.water in bucket is very sooty.any thoughts? See video.

 

[Tiki91]

2018 Mercury 3.5 four stroke outboard surging And running very rich no fuel mixture screw on carb hard starting also.water in bucket is very sooty.any thoughts? See video.

Got it figured vacuum leak on intake manifold to fuel pump.hole in pump diaphragm.