1992 Nautique runs too rich

[wrmann]

I just rebuilt the 4160 Holley carb on my 1992 Nautique, 351 Ford PMC. I took my time cleaning and rebuilding the carb as per several articles I got from the internet. The carb was set to the recommended settings. The engine started right away and idles fine with new spark plugs but the carb runs too rich. The new spark plugs, NGK's UR5, turned sooty black with 15 minutes. Any ideas where to go now?

[steelerguy]

Plug reading

Was this 15 min running in your driveway or out on the water?

You can not get a valid plug reading from running idle.

I would check them after your out on the water at WOT.

[wrmann]

The boat was in my driveway.

[1994SNRoughRiver]

I have a 1994 SN 196 with the same problem. It runs just fine, but the fumes are annoying. Any suggestions?