Large amount of soot when running on hose

[Free?Boat]

The last couple of times I have run the boat in the driveway it seems that the exhaust water has more soot than usual. What can this be a sign of?

 

[Maclin]

Re: Large amount of soot when running on hose

That comes from unburned fuel mix, can be due to overrich fuel mix, or weak ignition, or out of spec timing, or...