18 HP Vanguard running rich

[GerryB]

I have an 18 HP B&S Vanguard powered Walker Superbee that is running too rich. Black sooty smoke, new plugs sooty and greatly reduced power. The choke butterfly is fully open and air cleaner replaced. Is there an adjustable jet or other solution from experience by others?
All suggestions are appreciated, also if anyone know where I can locate a service/repair manual for both mower and engine, it would be appreciated.

 

[bertsmobile1]

This looks llike a double post so a short answer this time
Get a full rebuild kit
remove the carb ( not easy on a Walker ) and clean it then fit the complete kit
Pay careful attention to both the air filter & fuel filter on Walkers as it gets very very dusty under that catcher .