Small Engines (Lawn Mowers, etc.): Troybilt riding mower, briggs and stratton, air mixture

Question
John, this is a Troybilt 16HPB S HYDRO 48 SN#-130660100607 purchased in 1994. The mower runs pretty well, but blows black smoke and fouls plugs pretty quickly. I'm wondering about a carb. adjustment, or if it's something else. The mower has plenty of power.
If it's carb. adjustment, where are the adjusting screws?
Thanks

Answer
Hello Kelly:

The Engine Model is a Briggs and Stratton #294700. You can View a Breakdown/IPL of the Engine at this Site Addy, http://www.outdoordistributors.com/ and Select the B. Then Select Briggs and Stratton. Then Select Don't have Part Numbers. Then Select the File #29.  Then Select the Folder #294700. There is an Idle Air Adjustment on this Carburetor, but No Main Air Mixture Adjustment. I Suggest you Remove, Disassemble and Soak the Carburetor Overnight in Carburetor Cleaner (I use Gunk). Then Blow Out the Passages with Compressed Air. Install a New Kit if Required. With these Type Carburetors, Since they Don't have the Adjustment Screw for the Main Jet, All One can Do is Clean and Rebuild. The Carburetor is Flooding and Causing the Smoke and Fouling the Plugs. A Blue Tinted Smoke would Indicate Oil Burn. The Idle Air is Set so when Throttling from Idle to Full Throttle there is No Hesitation in the Engine. The Main Air Mixture is Self Regulated and Has No Adjustment. Hope this Helps. I am Here if You Require More Assistance. Let Me Know What Happens, Please. Thanks.

Good Luck

Respectfully  

John